A classic Fantastic Four villain makes the debut here in Ultimate form, turning the Baxter Building into a virtual trap set to capture and eliminate the fledgling adventurers. And what of the other denizens of the skyscraper, including Johnny and Sue's father Dr. Storm? And who has the power to outthink even the most brilliant man alive, Reed Richards? Wait and see! Plus: the first appearance of the Ultimate Inhumans! From a hidden race, she came to steal the heart of the FF's youngest member. She's the beautiful elemental called Crystal! Collects Ultimate Fantastic Four #19-20 and Annual #1.