Synopsis
A week after the Avengers joined together in Av#1 (after Loki pitted Hulk against the rest - Ant-Man, Iron Man, Thor and Wasp) they officially announce their formation. Tony Stark has let them use his New York mansion, and his butler Jarvis. Mr Fantastic thinks they're a good idea. Spider-Man thinks about joining them, after being turned down by the Fantastic Four in Amazing Spider-Man #1. However Dr Doom is not pleased about potential new enemies.
The public are suspicious of Hulk, despite his pardon in Hulk #6 for defeating the alien Metal Master. Thing recalls the army sending the FF after Hulk in FF#12, before the pardon. Meanwhile Hulk doesn't get on with his partners, especially Thor.
Major Bowman asks Avengers for help against Dr Doom. Ant-Man remembers helping the FF against Doom in a micro-world in FF#16, After he left them in FF#17 Doom attacked again immediately. Bowman describes how the military impounded Doom's flying fortress after that affair. But now the fortress has flown off, presumably under Doom's control again.
Bowman accompanies the Avengers in a helicopter in pursuit of the flying fortress. The male Avengers invade the fortress through a hole punched by Hulk, leaving Wasp, Bowman and the pilot in the helicopter. But the pilot is a robot agent of Doom, and captures Wasp with knockout gas.
The Avengers are caught in individually-tailored traps. Hulk in a room with frictionless surfaces and air blasts that keep him off-balance. Iron Man by a power-sapping robot. Thor by a swarm of power spheres which should eventually transport him to another dimension.
Ant-Man finds captive Bowman. But it turns out that he has been in the fortress all the time. The Bowman who came to the Avengers was actually Dr Doom in disguise. Doom has Wasp in a small transparent sphere. He now completes the set of traps by flooding Ant-Man and Bowman's compartment with a deadly gas.
But unknown to Doom (or the other Avengers) Ant-Man has just (in Tales to Astonish #49) learned how to grow as well as shrink. He pops a pill and becomes Giant-Man, bursting through the ceiling.
We learn at the end of the issue that Wasp has seen a displayed plan of the fortress showing where all the Avengers are. She transmits the info to Giant-Man. He then breaks into Hulk's room and drags him out. They see Thor's whirling hammer creating a vortex which destroys all the power spheres. And Hulk clobbers the robot draining Iron Man, while Thor uses lightning to recharge his batteries.
The Avengers burst in on Doom and free Wasp. Doom flees but Hulk catches him. And tears his head off! Except Doom turns out to be just another robot. Doom has been controlling everything from somewhere nearby.
The fortress is about to explode, and there's only one escape pod. Everyone, including Major Bowman, insists someone else should use it. Hulk settles the argument by shoving Bowman inside and hitting the eject button. Then all Avengers dive out of a hole in the flying fortress's side, as it blows up. And fly/leap to safety (Ant-Man and Wasp on Thor's shoulders).