Transformers (2007)

Several thousand years ago, the planet Cybertron was consumed by a civil war between the two Transformer factions, the Autobots led by Optimus Prime and the Decepticons led by Megatron. Optimus jettisoned the AllSpark, a mystical artifact that brings life to the planet, into space, but Megatron pursued it. Megatron crashed onto Earth, landing in the Arctic Circle and froze, and was discovered in 1895 by explorer Archibald Witwicky. Witwicky inadvertently activated Megatron's navigational system, which etched the AllSpark's coordinates into his glasses. The glasses end up in the possession of his great-great-grandson Sam Witwicky.

In the present, Blackout attacks and destroys a United States military base in Qatar in a failed attempt to hack the military network to find information on Megatron and the AllSpark. A surviving team of Army Rangers led by Captain William Lennox escape across the desert, pursued by Blackout's drone Scorponok. They fight Scorponok off, aided by aerial reinforcements, and travel home with Scorponok's stinger, discovering sabot rounds damaged its armor. At the Pentagon, Secretary of Defense John Keller leads the investigation into the attack. Sound analyst Maggie Madsen catches another Decepticon, Frenzy, hacking into the military network while onboard Air Force One. While the hack is thwarted, Frenzy downloads files on Archibald's glasses, tracking down Sam with Barricade, disguised as a police car.

Meanwhile, Sam buys his first car, a rusting Chevrolet Camaro, but discovers it has a life of its own. Sam and his high school crush Mikaela Banes are rescued from Barricade and Frenzy by the Camaro who turns out to be Autobot scout Bumblebee, who has to communicate through his car radio due to being mute. Previously sending a beacon to his fellow Autobots, Bumblebee takes Sam and Mikaela to meet Optimus Prime, Jazz, Ironhide, and Ratchet. Optimus explains the details of the situation, revealing that if Megatron gained the AllSpark he would transform Earth's machinery into a new army and exterminate mankind. Sam, Mikaela, and the Autobots travel to Sam's house to retrieve the glasses, but they are captured by agents of Sector Seven, a top-secret paramilitary government branch, led by Seymour Simmons. The Autobots stop the agents, but they call for backup, who take Sam, Mikaela, and Bumblebee into custody, while Optimus obtains the glasses, and uses them to locate the Allspark.

The humans respectfully connected to the Transformers are gathered together at Hoover Dam by Sector Seven's director Tom Banachek, who reveals Megatron, still frozen, and the AllSpark. Frenzy, having smuggled away in Mikaela's bag, disables Megatron’s cryonics system and summons Starscream, who in turn summons Brawl and Bonecrusher, the latter being killed by Optimus on a highway. Bumblebee is released to protect the AllSpark, shrinking it to a handheld size so it can be transported to safety. Megatron escapes the dam after thawing out. Frenzy attacks Secretary Keller, Madsen and Agent Simmons in the Dam's radio room, trying to prevent them from summoning the Air Force, but is decapitated by his own ricocheting shuriken.

A lengthy battle occurs in Mission City, with Blackout and Brawl dying at the hands of the military and Bumblebee respectively. However, Megatron kills Jazz and prevents Sam's attempted escape with the AllSpark. Optimus arrives to protect Sam, and engages in a battle against Megatron, with the latter getting the upper hand. Optimus tells Sam to push the cube into his chest to ensure their mutual destruction, but instead rams it into Megatron's chest, overloading his spark and killing him.

Optimus salvages a shard of the AllSpark from Megatron's mangled corpse. The United States government shuts down Sector Seven and disposes of the dead Decepticons in the Laurentian Abyss. Sam and Mikaela then start a romantic relationship while the Autobots secretly hide out on Earth, and Optimus sends a transmission into space inviting any surviving Autobots to join them.

A brief mid-credits scene shows Starscream escaping into space to rally other Decepticons and summon them to Earth.

Transformers: Revenge of the Fallen (2009)

In 17,000 B.C., the Seven Primes travel across the universe to create Energon with star-absorbing machines called Sun Harvesters, which destroy stars in order to collect their raw material. One of them defies the rule to never to destroy a planet with life by establishing a Sun Harvester on Earth, earning him the name "The Fallen". The Fallen is confronted by the other Primes, who imprison him before he can harvest the Sun using the Matrix of Leadership. The rest of the Primes then sacrifice themselves to hide the Matrix in an unknown location.

In the present, two years after the events of the first film, the Autobots and the U.S. military have formed the Non-biological Extraterrestrial Species Treaty (NEST), a classified international task force used to eliminate the surviving Decepticons. In Shanghai, the Autobots intercept two Decepticons, Demolisher and Sideways. Sideways is killed by the Autobot Sideswipe, while Optimus Prime kills Demolisher, but not before he warns them of the Fallen's return. At NEST's secure headquarters in Diego Garcia, National Security Adviser Theodore Galloway concludes that since Megatron's corpse is at the bottom of the Laurentian Abyss and the last-known AllSpark shard is secured in the base, the Decepticons must still be on Earth solely to hunt the Autobots. The Decepticon Soundwave hacks into a military satellite, overhears this information, and sends Ravage to retrieve the shard.

Meanwhile, Sam Witwicky is preparing to attend college, leaving his girlfriend Mikaela Banes and guardian Bumblebee behind. He finds a smaller AllSpark shard and picks it up, causing him to see Cybertronian symbols. As a side effect, the shard's energy brings various kitchen appliances to life, who then attack Sam and his family. After Bumblebee kills the living appliances, Sam gives the shard to Mikaela, who later captures the Decepticon Wheelie when he attempts to steal it. The Constructicons resurrect Megatron by brutally ripping apart the Constructicon Scrapmetal to provide parts, as well as using the stolen shard. Megatron then travels to one of Saturn's moons, where he reunites with his second in command, Starscream, and his master, the Fallen, who orders him to capture Sam alive and kill Optimus, as he is the only Transformer who can defeat the Fallen. After killing Alice, a Decepticon Pretender disguised as a college student, Sam, Mikaela and his college roommate, Leo are captured by the Decepticon Grindor and taken to an abandoned factory. Megatron reveals that the symbols in Sam's mind will lead the Decepticons to a new Energon source before Optimus and Bumblebee arrive to rescue the trio. Optimus engages Megatron, Starscream, and Grindor, killing the latter in the process. After the battle, Megatron kills Optimus by impaling him through the chest from behind, destroying his spark. The other Autobots arrive and attack the Decepticons, forcing Megatron and Starscream to retreat. The Decepticons launch devastating simultaneous attacks around the world, destroying ships in the Second Fleet and damaging Paris. The Fallen hijacks Earth's telecommunications systems, demanding that Sam be handed over to him.

Sam, Mikaela, and Leo enlist the help of former Sector Seven agent, Seymour Simmons, who reveals the Transformers visited Earth eons ago and the most ancient, known as Seekers, remained on Earth, hiding in secret. With help from Wheelie, they track down a Decepticon Seeker named Jetfire at the Smithsonian Air and Space Museum. They use their shard to revive Jetfire, who teleports the group to Egypt and explains the story of the Fallen. Following Jetfire's example, Wheelie sides with the Autobots, and Jetfire sends them to locate the Matrix, which could revive Optimus. Sam's group finds the Matrix in Petra, but it disintegrates into dust in Sam's hands. Undeterred, Sam stuffs the Matrix's remains into his sock.

Meanwhile, NEST forces and the Autobots land near the Giza pyramid complex but are attacked by a large force of Decepticons. During the battle, many Constructicons combine to form Devastator, who destroys one of the pyramids to reveal the Sun Harvester inside before he is killed by a US navy destroyer's railgun. Ravage and the Decepticon Rampage attempt to spring a trap, using Sam's captured parents as bait, in order to force Sam to give them the Matrix, but Bumblebee interferes and kills them both. Major William Lennox and Master Sergeant Robert Epps call in an airstrike that kills the majority of the Decepticon ground forces. However, Megatron manages to shoot Sam, mortally wounding him, before Megatron is forced to retreat. As Sam nears death the Primes contact him through a vision, saying that the Matrix must be earned, not found, and that he has now earned the right to bear it. They restore Sam's life and the Matrix, which he uses to revive Optimus.

The Fallen teleports to their location and steals the Matrix from Optimus, then returns to the pyramid with Megatron and activates the Sun Harvester. Jetfire, who was gravely wounded by Scorponok during the battle (but was able to kill his attacker), sacrifices himself in order to transplant his parts to Optimus, which gives Optimus immense strength and the ability to fly. He knocks the Fallen and Megatron off the pyramid, destroying the Sun Harvester in the process. In the battle, Optimus incapacitates Megatron and kills the Fallen; Megatron retreats with Starscream, vowing vengeance. The victorious Autobots and their allies then go back to the United States and Sam returns to college.

Transformers: Dark of the Moon (2011)

In 1961, the Ark, a Cybertronian spacecraft carrying an invention capable of ending the war between the benevolent Autobots and the malevolent Decepticons, crash lands on the dark side of Earth's Moon. The crash is detected on Earth by NASA, and President John F. Kennedy authorizes a mission to put a man on the Moon as a cover for investigating the spacecraft. In 1969, the crew of Apollo 11 lands on the Moon.

In the present, the Autobots assist the United States military in preventing major conflicts around the globe. During a mission to Chernobyl to investigate suspected alien technology, the Autobots are attacked by a giant Cybertronian worm-creature called the Driller and his master Shockwave, a Decepticon scientist. After the two escape, Optimus Prime finds the technology is a fuel cell from the Ark, discovering it had survived its escape from Cybertron. After learning of the top-secret mission to the Moon, the Autobots travel there to explore the Ark. They discover a comatose Sentinel Prime—Optimus's predecessor as leader of the Autobots—and five Pillars he created as a means of establishing a Space Bridge between two points to teleport matter. After returning to Earth, Optimus uses the energy of his Matrix of Leadership to revive Sentinel Prime.

Meanwhile, Sam Witwicky is frustrated that he is unable to work with the Autobots or find a job. He also becomes envious of the close relationship between his new girlfriend, Carly Spencer, and her boss Dylan Gould. After finding work, Sam is provided information by his eccentric co-worker Jerry Wang about the Ark, before Jerry is assassinated by the Decepticon Laserbeak. Sam contacts the now independently wealthy Sector 7 Agent Seymour Simmons, and together they realize the Decepticons and their leader Megatron are murdering people connected to the American and Soviet space missions to the Ark. They locate two surviving cosmonauts, who reveal satellite photos of hundreds of Pillars being stockpiled on the Moon. Sam realizes that the Decepticons raided the Ark long before the Apollo 11 mission to the moon and intentionally left Sentinel and the five Pillars for the Autobots to find, as Sentinel is the key to activating the Pillars and the Decepticons lacked the means to revive him. The Autobots fight off three pursuing Decepticons: the Dreads, and rush to return Sentinel to their base for protection, but Sentinel betrays them and murders the Autobot Ironhide, revealing he had made a deal with Megatron to ensure Cybertron's survival.

Sentinel uses the Pillars to transport hundreds of concealed Decepticons from the Moon to Earth. Carly is later captured by Dylan, who is revealed to be in service of the Decepticons. The Autobots are exiled from Earth at the demand of the Decepticons to avoid war, but as their ship leaves Earth it is destroyed by Starscream, seemingly killing the Autobots. The Decepticons, led by Megatron and Sentinel, invade Chicago as their agents place Pillars around the world. Dylan reveals to Carly that the Decepticons plan to transport their homeworld Cybertron to the Solar System, and then enslave humanity and use Earth's resources to rebuild their world. Sam teams up with former USAF Chief Robert Epps and several ex-NEST soldiers to go into Chicago to save Carly and arrest Dylan, but they are nearly killed by Decepticon forces before the Autobots intervene, revealing they concealed themselves during the launch of their ship to convince the Decepticons they were destroyed.

Working together, the Autobots, along with several ex-Rangers and Navy SEALs, manage to rescue Carly and kill Laserbeak, the Driller, Starscream, Soundwave, and Shockwave, with Optimus using Shockwave's arm-cannon to blast the Control Pillar, disabling the Space Bridge. During the battle, the Autobot Wheeljack is killed while Wheelie and Brains sneak on board a Decepticon warship and sabotage it. Sam confronts Dylan as he reactivates the Control Pillar, and knocks Dylan into the Pillar, killing him. Bumblebee and Ratchet arrive and destroy the Control Pillar, permanently disabling the Bridge and causing the partially transported Cybertron to implode, becoming badly damaged. Optimus and Sentinel fight while Carly convinces Megatron that he will be replaced by Sentinel as leader of the Decepticons. Sentinel severs Optimus's right arm and is about to execute him until Megatron, having listened to Carly, intervenes, incapacitating Sentinel. Megatron slyly proposes a truce, having the desire to become the one in charge again, but Optimus instead attacks Megatron, decapitating and killing him. Sentinel pleads for his life, but Optimus executes him too for his betrayal. With the Decepticons defeated, Carly and Sam are reunited and the Autobots, knowing that Cybertron is badly damaged, remain on Earth still; making it their temporary home.

Transformers: Age of Extinction (2014)

Sixty-five million years ago, an alien race known as the “Creators” used devices called Seeds to terraform Planet Earth, covering it with an alloy called Transformium. In the present day, geologist Darcy Tyril excavates the Transformium for K.S.I. Industries, which uses it to build man-made Transformer drones.

Five years after the Battle of Chicago, humans have begun to view the Transformers as a threat, leading the U.S. government to terminate all human-Autobot joint programs. Although the public believes the Autobots have been granted sanctuary, they are being hunted by a rogue CIA black ops division known as Cemetery Wind, led by opportunistic government official Harold Attinger, who believes all Transformers should be exterminated regardless of their faction. They are aided by Lockdown, a Cybertronian bounty hunter working for the Creators, promising to give Attinger a Seed if his division manages to capture Optimus Prime. Cemetery Wind locates Ratchet in Mexico City and Lockdown kills him when he refuses to give up the whereabouts of Optimus Prime.

Optimus, damaged in Mexico City and disguised as an old Marmon 97 semi-truck, is discovered in an abandoned theater by Cade Yeager, a financially struggling Texan inventor, and brings him back to his farm. While his teenage daughter Tessa and business partner Lucas Flannery encourage him to turn Optimus over to the authorities after realizing what he really is, Cade instead fixes Optimus, hoping to understand his technology and unexpectedly revives him. Still skeptical of Optimus, Lucas calls Cemetery Wind, who attacks and destroys the farm, but Optimus and Tessa's boyfriend, Irish rally car driver Shane Dyson, come to the family's aid. While on the run from Cemetery Wind and Lockdown, Lucas is killed by one of Lockdown's grenades. Escaping into the desert, they take refuge in an abandoned gas station. Later, Optimus gains an alternate form after scanning a passing Western Star 5700 XE Phantom Custom truck with the original red and blue paint with flames and summons the surviving Autobots – Bumblebee, who has assumed an alternate form (a 1967 Chevrolet Camaro), Hound, Drift, and Crosshairs – who have come to distrust humans due to Cemetery Wind constantly hunting them down. Using a CIA drone which he stole during the home invasion, Cade discovers K.S.I.'s involvement in the attacks on the Autobots. Optimus vows to personally kill Attinger for his actions against his brethren.

Infiltrating K.S.I.'s headquarters in Chicago, Cade discovers the remains of Autobots and Decepticons are being melted down to make the drones. Joshua Joyce, the ambitious company CEO, is in league with Attinger to revolutionize global defenses and improve human society using the Seed. He has captured Brains and used him and data from Megatron's head to create the drones and prototype Transformer soldiers Galvatron and Stinger. In a fit of rage, the Autobots storm the building, during which Bumblebee regains his original form by scanning a passing 2014 Chevrolet Camaro, where they rescue Brains and destroy the laboratory, but they soon leave after Joshua announces that they are no longer needed. Attinger forces Joshua to deploy Galvatron and Stinger to attack the Autobots. During the battle, Galvatron's behavior becomes slightly erratic when it starts destroying vehicles, and when it fights Optimus it speaks to him. Lockdown then arrives and abducts Optimus while Galvatron and Stinger retreat; Tessa is inadvertently captured alongside Optimus in the midst of the chaos, leaving Cade and Shane devastated.

While Lockdown's large prison spacecraft hovers over Chicago to hand over the Seed, Cade, Shane, and the Autobots use the opportunity to sneak on board and rescue Optimus and Tessa, hijacking a smaller ship containing a group of Autobots called the Dinobots, just before Lockdown leaves Earth. The Autobots reveal to Cade that "Galvatron" is in fact Megatron, who gave K.S.I. the data to build the Transformer drones so he could transfer his consciousness into the Galvatron drone, after they had unknowingly revived him. What's more, Galvatron is plotting to use the Seed and the K.S.I. drones to conquer the world by detonating the Seed in Hong Kong, as K.S.I. has brought it there to use it in the remote Mongolian desert to create vast amounts of usable Transformium. Cade informs Joshua of Megatron's presence, causing him to have a change of heart and agreeing to hand over the Seed with help from Darcy and his Chinese business associate Su Yueming. Meanwhile, Lockdown discovers Optimus' escape with the Dinobots, and returns to Earth to retrieve them. Optimus decides for the Autobots to no longer help the humans because of how they revived Megatron, but Cade explains to Optimus why he shouldn't lose faith in them. At the K.S.I. facility, during a disagreement between Joshua and Attinger over the Seed, Galvatron reactivates himself and promptly takes control of the K.S.I. drones, and a battle follows in Hong Kong's streets between Cade's group, the Autobots, Cemetery Wind, Galvatron, and his drones. During the fight, Optimus gains the alliance of the Dinobots, who become essential to the Autobots' victory while Bumblebee kills Stinger.

Lockdown returns to capture Optimus and the Dinobots, using a large magnet in his ship that picks up and drops metal objects, causing destruction to the city. After disabling the magnet, Optimus fights Lockdown at an abandoned factory. In the ensuing duel, Optimus kills Attinger (who still angrily deems all Cybertronians aside from Lockdown as a threat) to save Cade, and avenging the deaths of his fellow Autobots, but this allows Lockdown to pin Optimus down by impaling his chest with his own sword. Cade, Bumblebee, Tessa, and Shane fight Lockdown, with Cade ending up fighting him one-on-one while Tessa and Shane use a tow truck to free Optimus, who kills Lockdown by cutting him in half before using one of his grenades to finish off the remaining drones. Galvatron retreats, vowing to return.

As Lockdown's ship leaves Earth, Optimus tells the Autobots to protect the Yeagers (with Joshua offering to help the Yeagers build a new home) and lets the Dinobots go, before flying away into space with the Seed to hide it away, sending a message to the Creators that he is coming for them.

Transformers: The Last Knight (2017)

In 484 AD, King Arthur and his knights fight a losing battle against the Saxons. Elsewhere, Merlin approaches the Knights of Iacon, a group of Transformers hiding on Earth, to help win the war. They hand him an alien staff, before transforming together into Dragonstorm and turn the tide of the battle, but warn Merlin that a great evil will come for the staff.

In the present, three years after the Hong Kong Uprising,[N 1] in 2017, Optimus crash-lands on Cybertron, and meets his alleged creator Quintessa. She blames Optimus for Cybertron's destruction and brainwashes him into helping her gain Merlin's staff, which can absorb Earth's energy to restore Cybertron. Optimus is renamed Nemesis Prime. Earth is revealed to be the slumbering Unicron, the ancient enemy of Cybertron, and whose horns are emerging across the planet.

On Earth, Transformers remain unwelcome among humanity, apart from in Cuba, and are hunted by the Transformers Reaction Force (TRF), a paramilitary force manufactured from the fallen Cemetery Wind. However, the U.S. military, particularly those who had formerly worked with the Transformers, such as Colonel William Lennox, is secretly against the new policy. Cade Yeager, an ally to the Autobots, helps hide refugee Transformers from the TRF in his remote junkyard. In the war-torn Chicago, Cade, Bumblebee, young scavenger Izabella and her Transformer companions Sqweeks and Canopy help a group of children evade the TRF drones, but Canopy is killed by a fighter jet. Cade receives a mechanical talisman from a dying Autobot knight and has a brief standoff with the TRF and their leader, Santos, before being saved by Bumblebee, Lennox, and Hound. Cade returns to his junkyard with Izabella and Sqweeks with the talisman. Both Megatron and the U.S. government become aware of the talisman's value and power, reluctantly joining forces to obtain it. A group of Decepticon prisoners are released to aid in the mission.

The Decepticons and the TRF locate Cade's hideout with the help of a tracker previously planted on Bumblebee. Cade, his assistant Jimmy, Izabella, and Sqweeks flee from the Decepticons and the TRF to an abandoned town where the Autobots ambush their enemies and defeat them while Cade, Jimmy, and Izabella battle a unit of TRF drones. Cogman, a steampunk Transformer, appears and invites Cade to the United Kingdom to meet his employer, Sir Edmund Burton, who has connections to the Transformers. Burton also has another Transformer associate named Hot Rod who he orders to find Viviane Wembley, a University of Oxford professor, and bring her to him. On his way back, Hot Rod gains an alternate form after scanning a passing Lamborghini Centenario LP770-4 sports car.

Bringing Cade, Viviane, and Bumblebee together, Burton explains that Transformers have been aiding mankind in war for centuries, their existence hidden by a secret society of famed historical figures, the Order of Witwiccans, of which he is the last living member. The talisman can lead to Merlin's staff, buried with him in a Cybertronian spacecraft hidden under the sea. However, only a direct descendant of Merlin can wield it due to the knights encoding his DNA into it. Viviane is revealed as the last of Merlin's bloodline. The TRF and local authorities discover them, forcing them to flee. Following a series of clues while evading their pursuers, the group head to the Royal Navy Museum. There, Cade, Viviane, Bumblebee, and Cogman commandeer the museum submarine HMS Alliance, also a Transformer, to find the spacecraft. The TRF, after a failed attempt to stop the Alliance, pursue them in DSV submarines.

Burton contacts Seymour Simmons, both learning that Earth is Unicron, and the staff will be used to drain the planet's life, via an access point hidden under Stonehenge. Locating the ship, Cade and Viviane discover Merlin's tomb and obtain the staff. Viviane activates it, causing the spacecraft to become airborne, awakening the Knights of Iacon. As the TRF, now under Lennox, try to take the staff from them, Nemesis Prime arrives, forcing the humans to surrender the staff. Bumblebee, Lennox, and Cade confront Nemesis who engages in battle with Bumblebee. Just as Nemesis is about to finish him off, the formerly-mute Bumblebee begins speaking in his own voice (rather than the radio), stirring Optimus' memories and freeing him from Quintessa's control. The Decepticons ambush Optimus and Cade and steal the staff from him. The Knights try to execute Optimus for his "betrayal," but Cade stops them when his talisman transforms into Excalibur. The Knights yield and join the humans and Autobots. Burton tries to stop Megatron from activating the staff at Stonehenge only to be mortally wounded, dying peacefully with Cogman at his side. At the same time, Cybertron's remains collide with Earth to begin draining energy from it, devastating the planet and killing millions. The Autobots, Dragonstorm, and human military forces converge on Stonehenge and Cybertron, attacking the Decepticons and Quintessa's minions, who either flee or are killed while Quintessa is defeated by Optimus and Bumblebee. The worlds are then saved upon Viviane removing the staff and the Autobots leave Earth to rebuild what is left of Cybertron. In a mid-credits scene, Quintessa, who has survived by using a space bridge to escape and is disguised as a human, approaches a group of scientists inspecting one of Unicron's horns, offering a way to destroy him.

References:

https://en.wikipedia.org/wiki/Transformers_(film)

https://en.wikipedia.org/wiki/Transformers:_Revenge_of_the_Fallen

https://en.wikipedia.org/wiki/Transformers:_Dark_of_the_Moon

https://en.wikipedia.org/wiki/Transformers:_Age_of_Extinction

https://en.wikipedia.org/wiki/Transformers:_The_Last_Knight

*All Images/Gifs taken from Google Images*