Giant robots appear out of the mist and attack Montevideo, the capital of Uruguay. Accompanied by a squadron of spacecraft, they fire weapons at the city and destroy key buildings, leading to mass panic. The military fights back to little avail. At the end of the film, the robots fuse together to form a giant sphere, which then detonates and engulfs the city in a fireball. No explanation is given for the attack.
Taking place three hundred years prior to the events of the first film, the narrator describes how the government knew what was happening. A woman is seen driving recklessly in California while arguing over her cell phone. Police officer Ryan Hadley (Bruce Boxleitner) pulls her over and gives her a warning. The man calls her back, but she tells him off and throws the phone down; the phone then transmorphs into a robotic spider and kills her.
Five friends engage in a night of heavy drinking, fighting, and carousing at a club. Hung-over, they drunkenly stumble out of Robin's house, where they crashed for the night, and discover that nobody on their street has mobile phone service or power. They are confronted by an apparently deranged tramp who insists that they are in danger from people with a purple mark. When a city-sized spaceship hovers over Derby, the city begins to panic and society begins to break down. Michael, a lieutenant in the SAS, attempts to lead his friends to safety. He is accompanied by his new girlfriend Carrie, whom he met the previous evening at a nightclub, his best friend Robin, Robin's fiance Dana, and Vincent. They make their way to a store where their friend Pete works, but it is closed. The group rescues an immigrant from angry thugs, and Pete allows the group in through the side entrance. However, a riot breaks out when the crowd sees them gathering supplies, and looters attempt to steal their groceries. Michael frightens off the looters with a pistol, and the friends head back to Robin's house.
Miranda Hollander (Helena Mattsson) is a beautiful and smart young woman. She is a college professor and lives with her "uncle", Tom Hollander (Ben Cross) who works in a museum. Miranda can read books just by touching them, without even needing to open them. Miranda believes that she has lived with her "uncle" ever since her parents were killed in an accident while she was a baby. After her birthday, Miranda becomes unconscious and is sent to a local hospital. Tom is notified by the police. When Miranda arrives at the hospital, she silently transforms into alien form, strips naked and by seducing kills a few people. When Tom finally arrives at the hospital the following morning, he finds bodies everywhere. Tom locates Miranda, injects her with human hormone and begins to drive her to Mexico.
Three years ago, a team of astronaut miners completed a daring space expedition. They embarked on their journey home, but by the time the craft returned to Earth, their commander had gone mad—taking a terrible secret with him to a heavily guarded state asylum for the insane. Today, archeologist Lloyd Walker and entomologist Marianne Winters are among a select group of people who are questioning a possible link between the tragic space mission, the mystery of the commander’s madness, and a series of bizarre disappearances and strange accidents in San Francisco. The answer arrives when they stumble upon an underground colony of insect-like creatures harvesting human bodies for survival.
Astronomer Shinichi Tachibana, has a secret identity as superhero "Iron Sharp" (changed to "Space Chief" in the English dub) and has many children as friends. When they are attacked by a group of metallic aliens ("Neptune Men" in English), Iron Sharp drives the aliens away. Tachibana is also resourceful, as he helps develop an electric barrier to block the aliens from coming to the Earth. After several losses by the aliens, they announce that they will invade the Earth, throwing the world into a state of panic. As they invade the aliens destroy entire cities with their mothership and smaller fighters. Iron Sharp destroys multiple enemy ships and Japan fires a nuclear missile at the mothership, destroying it.
Not long after Megatron's demise and the restoration of Cybertron, the Autobots celebrate as Bumblebee is promoted to warrior class by Optimus Prime. The festivities end, however, when Optimus sets out on a journey to find the AllSpark, the source of new life on Cybertron, and takes Wheeljack with him to find it so that new Transformers can come into being. Ultra Magnus is left in charge in Prime's absence to hunt down the missing Starscream, Shockwave, and Predaking with the other Autobots. Meanwhile on Earth, at the bottom of the ocean, Megatron's consciousness is reawakened by Unicron, who seeks to destroy his arch-enemy Primus, the very core of Cybertron, and requires Megatron's body to do so. Unicron reformats Megatron into a body with new upgrades before heading to Cybertron. In the meantime, Ultra Magnus and Smokescreen continue to search for the fugitive Decepticons in the Sea of Rust, but are soon attacked by the Predacons Skylynx and Darksteel. After a brutal fight, Magnus is severely damaged and Smokescreen barely makes it through the space bridge with him. The damage is so critical that the Autobots are forced to call in Ratchet from Earth for assistance while the Autobots deduce that the two new Predacons must be creations of Shockwave. Meanwhile, Starscream and Shockwave are revealed to have restarted "Project: Predacon" and plan to create an army with Skylynx and Darksteel being their first creations.
The film begins with a woman (Emily Perkins) who runs to a nearby shop wanting to use the phone. She enters a phone booth, but is taken by an unknown creature. April (Brittany Allen) and her boyfriend Kyle (Freddie Stroma) are planning to go to her parents cabin for a romantic weekend alone, however she finds out that Kyle has invited his annoying friend Seth (Jesse Moss), Seth's girlfriend Lex (Anja Savcic), and another friend named Melanie (Melanie Papalia) along. Along the way, Seth sets off fireworks in the car and they are pulled over by Sheriff Murphy (Gil Bellows) who gives them a warning before letting them go. They finally make it to the cabin and begin drinking and smoking marijuana. Later on, Kyle proposes to April, which April rejects, angering Kyle. Suddenly they see something crash in the woods and upon investigating find that it's a UFO. After returning to the cabin they hear noises upstairs, and after getting April's father's gun find nothing but an open door. After finding an alien on the patio they shoot it to death. They then try and drive to town but find that the road is blocked.
In Gaea’s atmosphere the Jointrons and the Seacons battle each other but both factions are interrupted by the arrival of a large space ship which rams into them and sends them all flying into space before crash landing on the planet, and the Maximals and Predacons are immediately alerted. On the Galvaburg II, Gigastorm recommends destroying the ship but Galvatron is interested and believes it may hold good fortune for the Predacons. On the Yukikaze Lio Convoy orders a unit sent to investigate the ship but Lio Junior, Lio Convoy’s son, wishes to go but the other Maximals shoot him down, but Tasmania Kid stands up for him and asks if both can go and Lio Convoy approves and has Stanton and Skywarp accompany also. The 4 Maximals arrive at the ship and discover a “teleport gate”, an ancient device capable of opening a doorway into the past and transporting any living creature into the present, Transformers included but it requires a control unit to function. When Lio Junior finds it the Predacon Combaticons Hellscream, Dirgegun, Thrustor and Max-B swoop in and steals it but Lio Junior dives off after it alone and the Predacons overpower and nearly kill him, but before Hellscream can fire a finishing blow Kid takes the hit as the other Maximals arrive and scare off the Predacons and secure the control unit.
In 2021, aliens called "Heavies" invade Earth and make quick gains against a disorganized response from various nations. When the United Nations is disbanded and a united military front, the USDF (United Services Defense Force), replaces it, the aliens are driven off Earth, though thousands of their troops are left behind. A series of defensive satellites is thought to protect Earth from a second invasion. In 2033, two embedded journalists accompany reinforcements to a demilitarized zone between Pakistan and Afghanistan where Outpost 37, one of the last USDF outposts, is located. After a period of hazing, the reinforcements settle into life at the outpost.
Fifty people suddenly wake up in a darkened room, arranged in two concentric circles around a strange device. Noises sound when they attempt to move or touch the others. When someone ignores the warning and leaves formation, a beam from the device kills him. As the others panic, a man attempts to calm them. In mid-sentence, he is killed by the device. Thereafter, every two minutes, a sound signals that another person will be killed. After several people die, they realize they can vote for who dies. When nobody votes, one is selected randomly.