"Captives of the Deadly Duo!"
Part 2, "When Super-Menaces Unite"
Part 3, "When Friends Fall Out!"
Part 4, "Trapped!"
Part 5, "The End... or the Beginning?"
The Fantastic Four remain vigilant for the return of Doctor Doom, but can find no trace of him. Doom is busy introducing himself to the Sub-Mariner, fanning his hatred of surface dwellers and of the Fantastic Four.
Back at the Baxter Building, Johnny Storm has found that Sue keeps a picture of Namor hidden in her room. Just as they confront her about this, Namor appears. Namor offers peace with the team, but he secretly carries a device that has enabled Dr. Doom to pull the Baxter Building into outer space. Doom intends to fling them, Namor included, into the sun. Namor, realizing the double-cross, takes the fight back to Doom.