Rushing to investigate a disturbance downtown, the X-Men find Sabretooth on the rampage again, but realize too late that it isn't really Sabretooth at all. It is the Phalanx, a voracious alien life-form that can assume the guise of anything or anyone. Before long, the X-Men are all captured, except for Beast, who must find a way to stop the alien horror from devouring the entire Earth.
They are mutants, genetically gifted human beings - the world's newest and most persecuted minority group. Amidst an increasing climate of fear and bigotry, one enlightened individual, Professor Charles Xavier, has created a safe haven for some of these powerful outcasts. The mutants here are taught to harness their unique abilities for the betterment of the human race. They fight against hostile Government agencies and mutant supremacist Magneto, and his factions, which seek to destroy the human race.
X-Men: The Animated Series - The Phalanx Covenant (Part 1) Synopsis and Schedule