Transformers 2007: Cast, Plot, Box Office and Ending Explained

The full plot of Transformers (2007) runs from a civil war on Cybertron to a two stage battle on Earth. The Autobots and Decepticons fought over the AllSpark, a cube that can create life, on their home world. Megatron took the cube to Earth and crashed in the Arctic, where he froze and was found by Captain Archibald Witwicky in 1897. A secret government group called Sector 7 later built the Hoover Dam around the cube and studied the frozen Megatron.

In the present day, Decepticons attack a US base in Qatar and then pursue the knowledge held by Sam Witwicky, whose family heirlooms carry the key to the cube's location. Sam's car, Bumblebee, is an Autobot sent to protect him, and Sam and his friend Mikaela Banes meet the other Autobots led by Optimus Prime. Sector 7 agents arrive and take Sam and Mikaela into custody, and the Autobots help get them free.

The heroes and the Decepticons then fight at Hoover Dam and afterward in Mission City. Sam ends up carrying the AllSpark and fights to keep it from Megatron. He drives the cube into Megatron's chest, which destroys both the cube and Megatron. Optimus Prime keeps a fragment of the cube but accepts that Cybertron cannot be restored. The government disbands Sector 7 and sinks the dead Decepticons. Sam and Mikaela begin a relationship, and Optimus calls out to other surviving Autobots to come to Earth.

The ending of Transformers (2007) closes the AllSpark story and plants the seeds for the sequel. Sam rams the AllSpark into Megatron's chest, which kills Megatron and destroys the cube. Optimus Prime keeps a small shard of it, although he knows his home world cannot be brought back. The government shuts down Sector 7 and sinks the Decepticon wreckage in the ocean. Sam and Mikaela begin a relationship, and Optimus sends a signal inviting the surviving Autobots to make Earth their new home.

Why does the cube work as a weapon? In my opinion, the logic is the tidiest piece of the script. The AllSpark creates life, so putting it into the body of the strongest Decepticon is the one move that cancels both the cube and the villain at once. It is also the moment where a teenager with a car becomes the person who finishes the fight, which is exactly the boy and his car idea Steven Spielberg pushed for when he joined as executive producer in 2004. The set up pays off in a clean line: Sam started the film buying an old car, and he ends the Mission City fight as the only person able to carry the cube to Megatron.

How does it compare with the rest of the saga? The 1986 animated film ends its first big fight the other way round, with Optimus Prime defeating Megatron but being mortally wounded. Here, in my opinion, the rulebook is flipped: the villain dies and the leader survives, which is a gentler note for a PG-13 summer film. The boy and his car template also keeps coming back. In Bumblebee (2018), B-127 scans a yellow Volkswagen Beetle and a grieving Charlie Watson finds it, and in Rise of the Beasts Noah Diaz tries to steal a Porsche that turns out to be the Autobot Mirage. Age of Extinction runs a variation, with Cade Yeager finding a badly hurt Optimus in Texas. It could be argued that the 2007 film wrote the pattern the later entries keep reworking.

What does it set up? Optimus keeping a shard and calling other Autobots to Earth makes room for a larger cast, and it could be argued that the shard is the loose thread the next film picks up. In Revenge of the Fallen, set two years after the battle of Mission City, Sam finds a small leftover shard of the AllSpark, and the Decepticons revive Megatron. Perhaps that is why the first film still feels complete on its own while pointing at a franchise, and why Megatron's death turned out to be less final than it looked in the Mission City street.