Méndez was Kolp's First Lieutenant in Battle for the Planet of the Apes. He disagreed with Kolp's militaristic ways. In scenes deleted from the original release of the film, when Kolp went to battle with Ape City (made up of apes and humans who fled the Forbidden City before the war) with his mutant army, Méndez remained behind, supervising the team who safeguarded their "secret weapon"; the Alpha-Omega Bomb. Kolp ordered Alma to fire the missile if he were to be defeated. She promised to, but when Kolp lost the battle, and the default order to fire the missile at Ape City was received, Méndez instead rejected the order and dissuaded her from destroying the world, reminding everyone that using the missile would not just destroy the apes. Instead he suggested that if they venerated the fearsome object and preserved the missile through time, they would never lose hope or a sense of purpose. He became the new human (mutant) leader, and his attitude toward the missile became the code of the underground humans, who built their society to reflect that code. His successors in turn carried his name, as a reminder of their purpose. Completing the circle, in the second movie the leader of the mutants was also called Mendez and the implication is that those mutants, who worshiped that same bomb, were the descendants of this Méndez, who spoke so reverently about the bomb's power.