Uncanny X-Men #113

"Showdown!"
September 1973
Chris Claremont (author), John Byrne (penciler), Terry Austin (inker), Gaspar Saladino and (letterer), Mary Titus (colorist), Jim Shooter (editor)

While the X-Men are still infantilized prisoners in his Antarctic base, Magneto conducts a series of raids on research facilities in Australia and New Zealand, stealing equipment. After a failed attempt, though, Storm is able to free herself and the others using a pin from her headress and the skills she learned as a thief in Cairo. Magneto is viciously ambushed by the X-Men when he returns and the fight eventually damages the base, which was located under a volcano, enough that lava begins to flood the chamber. Magneto escapes, as do Beast and Phoenix, but they are left stranded in Antarctica, believing that the others are dead.

Comments

Admittedly it is a little hokey for Magneto to have a base in a volcano (besides being very James Bond villain-y, it's so impractical), but the issue is so packed with an effective action sequence and character details it's a small quibble. It's worth pointing out that we're still not quite to the point where Magneto becomes a "tragic anti-hero", but already Claremont has more or less stripped him of much of his "raving megalomaniac" persona.

Footnotes

This is the first time Storm's background as a thief and pickpocket is mentioned. And, yes, she is the only character that really gets a detailed backstory by this point.