The Titan Thanos, having succeeded in appropriating the six Infinity Stones and reassembling them on the Golden Gauntlet, was able to achieve his goal of pulverizing half the population of the Universe. Five years later, Scott Lang, a.k.a. Ant-Man, managed to escape from the subatomic dimension where he was trapped. He offers the Avengers a solution to bring back to life all the lost beings, including their allies and teammates: retrieve the Infinity Stones from the past.