While the Avengers are in space opposing a massive alien threat, Thanos and the Black Order launch an attack against the Earth. The Avengers journey into deep space, where they unite the intergalactic races against the Builders--deadly aliens who seek to destroy the known galaxy. While the heroes are gone, Thanos sets his sights on Earth, sending the Black Order to launch the assault. It falls to the Inhumans, Black Panther, Doctor Strange, the X-Men, and more to defend the planet.