Complete story — includes the ending
Professor X has lost mental contact with the X-Men and, through Cerebro, sees that El Tigre has obtained the second half of a mystical amulet that transforms him into the earthly reincarnation of the Mayan god Kukulcán. Held back by a security guard under Kukulcán's control, Cyclops is forced to use his optic blasts to destroy the guard’s gun, and the shock releases the guard from El Tigre's mental domination. Pushing the guard aside in order to go after his enemy, Cyclops attempts to blast Kukulcán but his optic blast strikes the pendant and is redirected back at him with doubled force, knocking him out.
Kukulcán's hired mercenaries, Toloc and Ramon, enter the room and attempt to take the amulet from Kukulcán's chest so that they might sell it on the black market. The pathetic attempt is easily stopped by Kukulcán who unleashes the energy of the sun itself, striking them with an irresistible wall of heat and force that knocks them senseless. With his new powers, Kukulcán decides that he must return to Santo Rico where he will restore the kingdom of the Maya to its ancestral glory. Traveling to the roof of the museum, he creates a solar energy sphere around himself and uses it to fly back to Central America. While monitoring from afar via his mental powers, the Professor detects that El Tigre has left the area and so he is now able to use his mental powers to revive Iceman, Angel, Beast, and Cyclops. Xavier then orders them to go to Rendezvous Point C and to leave Ramon and Toloc behind for the police.
The next morning, the Professor calls Jean at Metro College to aske her to bring him books about Maya history and legends. Jean is concerned that the Professor chose to call her on the telephone instead of contacting her telepathically, leaving her to wonder if she is still considered part of the X-Men. Later, as Jean checks out books from the college library, Ted Roberts enters the room and introduces her to another student, Calvin Rankin. Jean remembers Rankin from her encounter with him when he became the costumed criminal Mimic. When Rankin mentions that he has the strangest feeling that he's met Jean before and asks if they have, Jean recalls that the Professor had removed his memory of meeting the X-Men so Jean keeps up the ruse and says they haven't met. However, Calvin is secretly sure that he's seen her before and won't rest until he remembers where.
Two hours later, Jean arrives at the X-Mansion where she gives the Professor the books he requested. After looking through them to find any mention of the stolen pendant, the Professor briefs them on the legends of Kukulcán. Xavier tells them that centuries in the past, when the pendant's divine power was misused, it caused a holocaust of violent upheaval that had showered a Maya city with tons of molten lava, an event that modern archeologists, rejecting the legend of a man with the power of a god, had assumed was inspired by a volcanic eruption. With the briefing over, Xavier orders the X-Men to travel to Santo Rico to stop Kukulcán. Jean expresses concern to Scott when she hears that he was injured in battle, but Cyclops has managed to shake off the injuries he sustained battling Kukulcán.
As the X-Men race to Santo Rico in their jet, Kukulcán has already returned to where the pyramid is located and begins to clear it of overgrown vegetation with his vast powers. The first object that he chooses to uncover is the true and ultimate source of all his powers, a gigantic plumed serpent stela with the huge Solar Stone atop it. After using his now-increased powers to clear the pyramids and the city of vegetation, Kukulcán sits upon the pyramid's throne and uses his powers to mentally enslave all those Santo Ricans who are descendants of the ancient Maya and compel them to travel to the restored Maya capital.
After the X-Men arrive in Santo Rico, they set up in a building where the Professor stays while the teens begin traveling upriver to where the jet's portable Cerebro unit indicated Kukulcán is located. Along the way, the X-Men use their powers to avoid attacks from the various wild animals in the region. Their motorized dugout is eventually wrecked in rapids but by then the X-Men are close enough to their destination for the Beast to spot the pyramids from high in a tree. Their presence does not go unnoticed, as a signal from the jungle alerts Kukulcán of the X-Men's arrival. As the X-Men continue their approach, they fall victim to a pit trap covered by grasses and are menaced by a small group of spear-wielding natives. However, this proves to only be a minor setback as Cyclops has Iceman create an ice shield that both protects them from the spears and hides them from view, enabling him to use his optic blast to dig them a tunnel out of danger without their captors seeing. Once they're all free, they knock the natives into their own trap.
Getting past Kukulcán's armed guards, Santo Rican policemen who have fallen under his control, the X-Men try to attack the powerful demi-god but find his powers to be too great for them to face. When Iceman needs to renew his powers, he happens to rest near the Feathered-Serpent idol which leads the Beast to notice that the glowing Solar Stone at its top is made of the same mineral as the pendant and is red-hot, probably because it's absorbing solar energy. Hearing this, Iceman deduces that the stone is El Tigre's power source and he begins using his ice powers to coat it with a thick layer of ice to block the sun's rays. As the other X-Men fight Kukulcán, his sixth sense enables him to evade the Angel's dive-bomb attack, causing Cyclops to accidentally strike Angel with his optic beams, shaking the group’s leader because his worst nightmare has come true; he's harmed one of his friends with his optic blast. Kukulcán then simply blasts Cyclops aside, then sees that Iceman is trying to isolate him from the source of his powers. When Kukulcán tries to stop him with a solar bolt that falls short, he realizes that the mutants have been trying to trick him into using up all his energy. Desperate to stop them, Kukulcán channels all of his might into a solar bolt that he fires at the base of the idol in an attempt to shake Iceman off of it. However, this proves to be Kukulcán's undoing as his blast not only shakes the idol, it also strikes an underground fault line, triggering an earthquake. As the idol begins to crack and break up, the courtyard in which it stands opens up into a yawning abyss which swallows up both the idol and the Solar Stone. Then, as the fissure closes and the city begins to collapse, Kukulcán flees to the temple atop the pyramid where, since the Solar Stone can no longer provide the pendant with power, the god reverts back to being the powerless El Tigre who the Beast has to rescue from the temple. With the city crumbling and aflame, the two X-Men tie up El Tigre and seek out their two comrades. Finding them outside the city, where Cyclops had managed to carry the Angel, Iceman and Beast see that Angel is injured but, before Cyclops can explain what happened, Warren briefly comes around and in a state of delirium accuses Cyclops of blasting him on purpose because he is jealous of Warren's mutual love of Jean before passing out again.
Cyclops knows that this is not true and that Angel is delirious and would like to believe that both Beast and Iceman know this also. However, as they walk silently away from the ruins, the X-Men's brooding leader cannot help but doubt.
Sources and content license
Source and revision history ↗ · Adapted from Marvel Database contributors, X-Men Vol 1 26. Illustrations and reference markup removed; synopsis paragraphs combined. · Content license