The Avengers Vol. 1 (1963-1996) #110

Plot

Guest-starring the X-Men. Magneto is back! And as depicted on the fabulous cover, he's already trashed the Uncanny X-Men...and the Mighty Avengers are next! The story begins in the Avengers' meeting room when a strange video starts playing on the communication screen. The video shows a large ransacked mansion and a beleaguered man lying next to a wheelchair. Is that Professor X? The thunder god thinks so! But unfortunately the Avengers don't know where the professor's school for gifted youngsters is located! However after searching for a while, Earth's Mightiest Heroes start finding things! First, they find the X-Men's home, then Cyclops, Marvel Girl, and Iceman out cold on the floor; and finally, big-time trouble! Flying boulders, rampaging dinosaurs, and oh yes, the Master of Magnetism himself! (mycomicshop.com)