Tony Stark (Robert Downey Jr.) tries to restart an abandoned peacekeeping project, but it turns out to be the fuse of a crisis. The world's most powerful superheroes - Iron Man, Captain America (Chris Evans), Thor (Chris Hemsworth), Hulk (Mark Ruffalo), Black Widow (Scarlett Johansson) and Hawkeye (Jeremy Renner) - have to accept the ultimate test to save the Earth in danger. The mysterious villain Ultron (voiced by James Spader) gradually rises, and the superheroes must regroup and try their best to stop Ultron from implementing the human extinction plan. During the battle, the Avengers also encountered two new characters, Wanda Maximoff (Elizabeth Olsen) and Pietro Maximoff (Aaron Taylor-Johnson), as well as an old friend who returned with a new look, Vision (Paul Bettany). The world order is on the verge of collapse, and the Avengers must stop Ultron's conspiracy. Powerful enemies continue to emerge, and an unprecedented global war is about to begin...