Fantastic Four versus the X-Men # 1 1987 NM-

Fantastic Four versus the X-Men # 1 (1987) is about the X-Men seeking help from Reed Richards to save a dying Kitty Pryde while a massive secret from Reed's past threatens to tear the Fantastic Four apart and drives the two teams into conflict. 

• Kitty Pryde's Condition: Following the events of the "Mutant Massacre," Kitty Pryde (Shadowcat) is gravely injured and cannot control her phasing ability, causing her body to start disintegrating. With nowhere else to turn, the X-Men, led at the time by a reformed Magneto, seek help from the "smartest man alive," Reed Richards of the Fantastic Four.
• Franklin Richards' Dream: The issue opens with young Franklin Richards having a vivid, precognitive nightmare of an amalgamation of his father and Doctor Doom killing the Fantastic Four and the X-Men, all stemming from an old journal of Reed's.
• Sue's Discovery: Franklin tells his mother, Sue Richards (Invisible Woman), about his dream. Later, she finds the very same journal in a crate and reads a terrible entry that suggests Reed might have intentionally exposed his teammates to cosmic rays during the original rocket flight, hoping to create a "fantastic foursome" to gain public support for super-humans.
• The Conflict Begins: Magneto approaches the Fantastic Four on Muir Island to ask for help, but the long-standing distrust of the X-Men's former arch-villain causes immediate tension. Reed initially agrees to help, but his newfound self-doubt, brought on by the discovery of his journal and the possibility of his greatest failure actually being a calculated risk, makes him hesitate.
• The Clash: Reed's apparent refusal or inability to confidently use his experimental device to help Kitty angers the X-Men, especially Wolverine, who attacks Mr. Fantastic, sparking a major battle between the two superhero teams.
• Doctor Doom's Involvement: A shipwrecked sailor rescued near Muir Island is revealed to be a robot sent by Doctor Doom, who sends an ominous message offering his aid to cure Kitty Pryde where Richards has failed, setting up a desperate bargain for the X-Men in later issues.