Uncanny X-Men Vol.1 #132
Deciding to become proactive, the X-Men attempt to infiltrate the Hellfire Club's inner sanctum. However, they soon discover that they may have played right into the hands of their mysterious foes when they run into the Inner Circle of the Hellfire Club.
Printed: Apr 1980
Writers: Chris Clairemont and John Byrne
Art: John Byrne and Terry Austin
Cover: John Byrne and Terry Austin