After serving a few years in prison, former burglar Scott Lang is released. Now wanting to be straight, Scott sets out to find himself a job. But he is totally unaware that his record is preventing him from working and seeing his young daughter Cassie. When he steals a powerful suit, he quickly returns it only to find himself arrested again. But a mysterious man named Hank Pym has other ideas for him. Pym explains that it has the power to shrink in size and increase in strength due to a special formula called the Pym Particle. He was once its owner and called himself Ant-Man. Unfortunately during his SHIELD days, Pym discovers that others wanted to replicate his design. Now Pym wants to use Scott to being the new Ant-Man because his former apprentice Darren Cross is working to replicate the formula for his own evil purposes. So Scott and Pym, along with Pym's daughter Hope must plan a heist that will stop Cross and save the world from certain chaos.