The X-Men are briefed about their next mission. Magneto seeks to make the powerful ruler of Atlantis, the Submariner, his ally. Just a few days ago, Xavier discovered that Magneto had invented a weapon that magnifies his powers. Xavier suspects Magneto has plans in seeking the collaboration of the Submariner.
The X-Men travel to the North Atlantic Ocean to search for Magneto. While scouting the area, Angel flies into the Submariner. The latter wants to take Angel to Magneto. Angel puts up a fight, but is knocked out by the Submariner. With teamwork, the X-Men rescue the falling Angel.
Professor Xavier’s use of telepathy to communication with Angel has alerted Magneto to the X-Men’s presence. Cyclops orders everyone to abandon their ship immediately. Magneto destroys the ship, thinking the X-Men had perished. The X-Men make their way onto Magneto’s island.
Cyclops and Angel make their way past Mastermind’s illusion of a huge man-eating plant to reach Magneto’s fortress at the centre of the island. They encounter Quicksilver, who quickly assaults Cyclops. Marvel Girl comes to his aid.
Meanwhile, Magneto is furious at the Submariner’s incompetence and blasts him through a brick wall. Magneto and the Submariner get into a fight, only to be broken up by Cyclops’ optic blast. Magneto orders his Brotherhood to retreat into the fortress. Scarlett Witch remains outside in search of her brother, Quicksilver, held by the X-Men. The Submariner is left outside as well.
Xavier instructs Marvel Girl to bring forth a “telepathically sedated” Quicksilver to try and reason with the Submariner that Magneto is just using him as a pawn in his plans, to fight the X-Men.
Enraged, the Submariner vows revenge on Magneto. Destroying Magneto’s fortress in mere minutes, the Submariner finds that Magneto has escaped.
Xavier is pleased with the day’s achievements, having successfully thwarted Magneto’s plans and ruined his alliance with the Submariner.