The X-Men save a group of orphans from a fire while returning Marvel Girl to her new school.
Meanwhile, in the jungles of Central America, El Tigre finds the ruins of the Kukulcan pyramid. There he finds a glowing gem, half of the sacred pendant of Kukulcan, which bestows great mental powers on the wearer. Further, if the two halves can be joined the wearer will "enjoy power without limit - if he survives its dread curse!"
Back in New York the X-Men are alerted to El Tigre's arrival by Cerebro and the four young men go in search of this man with frightening power.
They track El Tigre to the museum and have to fight against his minions while he searches for the other half of the amulet.