Thanos completes his Infinity Stone collection and the Super Hero Squad faces him in a final showdown for the fate of the universe. However, when requesting backup from one of their own, they encounter a betrayal that changes everything.

After being thrown into a portal by Dark Surfer, Falcon and H.E.R.B.I.E. find themselves in an alternate reality where Scarlet Witch is an evil empress who rules the world. With help from an elderly Magneto and a strong Reptil, Falcon and H.E.R.B.I.E. must try to convince Scarlet Witch that she is good and let the world be in peace.