After the devastating events of Avengers: Infinity War, half of all life in the universe has vanished due to Thanos' snap. The remaining Avengers and their allies struggle with loss and failure, but when Ant-Man presents a plan to travel through time using the Quantum Realm, hope is reignited.
The team embarks on a daring "time heist" to collect the Infinity Stones from the past, facing old enemies and revisiting key moments in their history. After successfully gathering the stones, Hulk uses them to bring everyone back. However, Thanos from the past discovers their plan and launches a massive attack.
In the epic final battle, all the resurrected heroes join forces against Thanos and his army. Ultimately, Tony Stark sacrifices himself by wielding the Infinity Stones to defeat Thanos and save the universe. The film ends with the Avengers mourning their loss and Captain America passing his shield to Sam Wilson, marking the end of an era.