Ben Affleck plays Michael Jennings, a brilliant engineer. When he is hired to do a job for a man named Rethrick, he is told he will be paid nearly $90 million dollars. However, at the end of the job, he must have his memory erased of the job. Three years later, Jennings has his memory erased and goes to collect his $90 million dollars. However, instead of that, he finds an envelope with simple objects that seemingly don't connect together that he had sent to himself while he was working for Rethrick. The FBI come after him because of the job Rethrick had given him. Jennings has to find out what he was doing the past three years using the envelope and its contents.