Not a single defense system on Earth has worked. The Avengers are trying to figure out what they are dealing with and discover an ancient race that has decided to cleanse the Earth and create a new, perfect form of life on it. The first attack came from Mars, and the Avengers are sent into deep space to unite the Kree, Skrulls, the Shi'ar Empire and other alien races warring against each other against a common enemy - the Builders. When the Earth was left without its main defenders, Thanos sent troops to it. Led by the Black Order, his army captured city after city. The remaining heroes on the planet - Iron Man, Doctor Strange, Black Bolt and Black Panther - will have to repel this invasion at all costs.