The main story reprints The X-Men #99 - Deathstar Rising! (June, 1976) with the inclusion of some new panels. The back-up feature, illustrated by John Bolton, illustrates the rise to power within the Hellfire Club of Sebastian Shaw, but at the cost of the woman he loves.
Retroactively the first appearance of the Hellfire Club (who would not appear until The X-Men #129, 1980).
Out with the Old
At an exclusive party at New York's Hellfire Club, Sebastian Shaw, Black King of the club's secret society, meets with the club's President and White King, Ned Buckman. Buckman introduces his White Queen, Paris Seville, and they exchange flattery before mentioning something called "Project: Armageddon".
Shaw seems confident in his pragmatic relationship with Buckman, despite the doubt cast by his date, Lourdes Chantel, to whom it seems obvious that Buckman hates mutants like Shaw and herself. Shaw's assistant Tessa likewise seems doubtful of Buckman's intentions, leading Shaw to make telepathic contact with Emma Frost, who's engaged in a clandestine mission upstate. Emma informs Shaw that Lourdes and Tessa are right to be concerned, as she's discovered that Project: Armageddon has seemingly changed it's goal from enhancing the club's wealth and power by controlling mutants, to the eradication of mutants altogether.
Shaw is furious to have been so deceived, but before he can confront Buckman, he gets a telepathic impression of Emma being attacked on her mission by a Sentinel. Realizing that Emma and fellow mutant Harry Leland stand little chance against the machine on their own, Shaw orders Lourdes to teleport the two of them and Tessa to where they are being attacked, despite her protests that she has never teleported that far with two extra people.
As they arrive on the scene, Shaw attacks the Sentinel head-on, counting on his growing strength to destroy it, but becoming ensnared by a metal cable before Lourdes can teleport him free. The Sentinel then impales Lourdes with a harpoon. Leland, feeling like a coward for not attacking sooner, uses his power to cause the robot to sink deep into the ground, an effort that seems to cause him much pain, as Shaw continues dismantling it even as he marvels at it's construction. The machine stopped, the mutants attend to the now dying Lourdes, and Shaw swears his revenge.
Back at the Hellfire Club, Buckman has assembled the members of the Club's inner circle, save for Shaw, explaining that the mutant threat within the club is being dealt with presently. As he speaks, he takes a firearm from one of the guards, then shoots him and the rest of the guards before opening fire on the remaining members of the inner circle, killing them all. Baffled and horrified by his own actions, Buckman is finally confronted by Shaw, who has disabled the room's telepathic dampeners allowing Emma to take control of Buckman's body.
Shaw, disgusted with Buckman's treachery, says that he wasn't his enemy until he made him one, and that a man is only as good as his word, before breaking Buckman's neck and claiming control of the new inner circle, naming them the Lords Cardinal in honor of the fallen Lourdes