The Four were captured upon their arrival to the Ultimate universe, and have been kept in a special holding cell designed by Mister Fantastic to contain the Hulk. They escaped in "Ultimate Fantastic Four" #31, tricking the guards into thinking they'd teleported out when really they had merely turned invisible. They were quarantined to the top 40 levels of the Baxter Building where they kill and eat anyone who was trapped with them. The group begin work on a portal which would allow their fellow zombies to gain access to this universe.