The Cure

S1, E9: A doctor at the Muir Island Mutant Research Center claims to have found a cure for the mutant gene. Rogue travels to the island seeking the "cure". Rogue visits Dr. Adler and tells him how she is considering the treatment. Dr. Adler sends her on her way and Apocalypse appears. Dr. Adler reverts to Mystique and they discuss Rogue's powers. Later Cable attacks Dr. Adler but the X-Men defeat them, and Rogue changes her mind about the treatment and leaves. Near the end, Warren (Angel) comes for the treatment and goes into Dr. Adler's lab. Later, Mystique finds Apocalypse and tells him of Warren, and he replies that he is planning on destroying the world.