The Guardians of the Galaxy & the X-Men join forces when they hear about the Black Vortex, a powerful mirror that can give anyone who looks in it cosmic powers. They must find it before those who would use it for evil. Meanwhile, J'Son, former king of Spartax, has escaped from jail, places a bounty on the Guardians of the Galaxy and teams up with Nebula & the Brotherhood of Mutants to steal the Black Vortex. (Based on the 2015 Marvel Comics story of the same name)