In Ultimate Fantastic Four #32, The Ultimates gathered at the foot of the Baxter Building as plans were made to drop the field and attack the zombies, when Doom in Mister Fantastic's body returned. Claiming that his first priority was helping Johnny Storm, he cast a spell to remove the creature that was killing him. However he miscast the spell, having partially translated it wrong, and the creature, while being drawn out of Johnny successfully, was not sent back to the Negative Zone. It remained on Earth, and immediately sought out a powerful host. Most thought it was Thor, but the parasite bypassed the Thunder God completely, possessing Reed in Doom's body, Reed having followed the FF back to the city. He went in to confront the Frightful Four; the zombies were pleased that they did not need to call their friends and thus share the 'food.' Reed killed the undead Human Torch first, releasing a chemical from his mouth that encased and crushed him in concrete-like 'vomit.' The undead Thing attacked next, mockingly asking if Doom was a hero in this reality, but Reed used Doom's strength to easily rip off the undead Thing's arm and shatter him with it. The undead Mister Fantastic and Invisible Woman attacked next, but Invisible Woman's powers seemed to have no effect on him, Doom's steel body protecting Reed from her force fields. He used Doom's magic to speed up the rate of the undead Invisible Woman's decay, rotting her to bones and dust rapidly. The zombie Mister Fantastic, panicking and enraged, demanded to know what was going on. Reed responded by using Doom's magic again, summoning hordes of maggots and other bugs and creatures that eat necrotic flesh to devour his undead counterpart from within.
