一声响指，宇宙间半数生命灰飞烟灭。几近绝望的复仇者们在惊奇队长（布丽·拉尔森 Brie Larson 饰）的帮助下找到灭霸（乔什·布洛林 Josh Brolin 饰）归隐之处，却得知六颗无限宝石均被销毁，希望彻底破灭。如是过了五年，迷失在量子领域的蚁人（保罗·路德 Paul Rudd 饰）意外回到现实世界，他的出现为幸存的复仇者们点燃了希望。与美国队长（克里斯·埃文斯 Chris Evans 饰）冰释前嫌的托尼（小罗伯特·唐尼 Robert Downey Jr. 饰）找到了穿越时空的方法，星散各地的超级英雄再度集结，他们分别穿越不同的时代去搜集无限宝石。而在这一过程中，平行宇宙的灭霸察觉了他们的计划。
注定要载入史册的最终决战，超级英雄们为了心中恪守的信念前仆后继……
A veteran CIA hitman that has been receiving orders via the classified ads section of newspapers, but now his long-lost daughter, a UK M16 analyst, tracks him down to reveal that his CIA boss has been dead for years.
Dominique, a well-trained assassin, flees from her troubled past in an attempt to begin a new life in South America. However, she soon finds herself in a town plagued with violence and corruption. Facing brutal attacks from the police and mafia, Dominique must decide whether to protect herself or an innocent family that has taken her in.
