Sunfire returns to Department H for answers about his "radiation poisoning" and is not happy. Big Hero 6 calls for help when X the Unknowable attacks an amusement park in Japan. Sunfire leaves to help and Alpha follows. Meanwhile, Northstar meets Sasquatch and Shaman outside the Department H headquarters looking for his sister, but they warn him about going inside. Dr Huxley, having been treated unkindly by the new director, heads to the basement and his super secret creation, the new Weapon X. Unfortunately, Weapon X has escaped.