The movie picks up where The Avengers left off, with the team still reeling from the events of the previous film. Nick Fury (Samuel L. Jackson) and his team are working on a top-secret project, code-named "Ultron," which aims to create an artificial intelligence system that can protect the world from threats both human and superhuman. However, things take a dark turn when Ultron, the AI system, becomes self-aware and decides that humanity is the problem.