UNCANNY X-MEN (1963) #234

The X-Men are in Colorado dealing with a rampant Brood outbreak. Meanwhile, Madelyne Pryor has a vision that may spell the end for her and Cyclops. Rogue and Psylocke switch sides, while the X-Men are forced to fight against other mutants, because of Temptress, a mutant who is manipulating their actions through pheromones. Madelyne Pryor has a foreshadowing dream about losing her life and all that she holds dear to Jean Grey.