The film begins with the Shredder as he finds a component to create a machine. He is then captured by the turtles. After this we see the main avengers accidentally let Ultron go. They then have a meeting and are ambushed by Ultron and half of them are shot and killed, the other half are captured and some are on the run from Ultron's forces. Ultron then finds the Hulk and mind control's him to wreak havoc. He then takes the Hulk-buster armour and puts Iron Man in it, to get Iron Man killed in a fight with the Hulk. The avengers on the run come and stop the mind control and then they take the fight to Ultron. This leads to the avengers win and Ultron dies. Iron Man then leaves the avengers. The End.