Vision convinces Dr. Doom to release his teammates and join them against Attuma. They locate the Atlantean warlord by following the beacon used to power the slave discs that controlled the Avengers. Sub-Mariner allies with Wonder Man and Whizzer and together they follow a tracking signal Beast sends them from Attuma’s flagship. The heroes converge on Attuma’s undersea base and battle the villain’s soldiers and Tyrak, whose size and strength is increased through the cell stimulator Attuma stole. Vision and Wonder Man beat Tyrak and Sub- Mariner defeats Attuma. Learning that Doom took the cell stimulator for himself, the Avengers follow him back to Hydrobase and Vision destroys the device. Doom escapes.
Attuma’s men subdue and enslave the Avengers and send them to Hydrobase, where Dr. Doom captures them (Av #154-155, ’76-’77).
Captain America’s brief disappearance near the end of this story is explained in SVTU #10, ’77 (not SVTU #11, as noted in an editor’s note) as an investigation of a spy ship hovering above Hydrobase.
