Los Hombres X #4

In "La Hermandad de los Malos Mutantes," Magneto leads his new Brotherhood of Mutant Villains in hijacking a cargo ship to seize control of the South American nation of Santo Marco. The X-Men launch a daring invasion to reclaim the country, but during the battle, Professor Xavier is caught in an explosion that strips him of his psychic abilities. Written by Stan Lee and illustrated by Jack Kirby with inks by Paul Reinman, this 1966 issue features cover art by Jack Kirby and George Roussos.