Hawkeye becomes upset with Hercules, because, while he, Quicksilver and the Scarlet Witch are trying to make battle plans to rescue Hank and the Wasp, Hercules is eating groceries! Pietro defends that Hercules is still their guest and not a real member of the Avengers, but Wanda partly sides with Hawkeye. Hercules shouts that Hercules may be a big man on Olympus, but defends that he still has a great deal to learn about Earth habits. Hercules starts shouting back, but Wanda manages to calm them both down, and Hercules and Hawkeye apologize to one another.
Pietro takes off, thinking it might be a good idea to contact the Fantastic Four, even though they are on holiday, since he remembers they were the first to battle the Dragon Man and wants to ask them for help. Plus, they might know something about Diablo’s castle in Transylvania. Pietro walks to the communication devices and tries to contact Mr. Fantastic. Both Reed and Ben answer the call. Ben finds it hard to believe someone could lose sight of the Dragon Man, but Reed silences him. Reed also warns the Avengers about the great danger Diablo represents, as he’s a century-old madman on a conquest to rule the entire Earth. Pietro knows that and asks Reed for a map of Diablo’s old castle. Reed agrees to hand it over and does so via the computer.
Quicksilver goes to tell his teammates about the news, and mentions that Reed offered his team’s help in the search for Diablo, but Pietro thought it would be better if the Avengers attempted to rescue their own by themselves. Hercules agrees to join the Avengers on this mission and, a few minutes later, they depart.
(Transylvania, Diablo’s rebuild castle)
Diablo notices that Goliath has woken up and brings him to his lab, where he decides to reveal something to the super-hero. Hank takes a look at the Dragon Man standing nearby, but finds it hard to believe he’s standing so still. Diablo reveals that that’s because this isn’t the same Dragon Man that Hank fought earlier. Diablo shows Hank several copies of Dragon Man, explaining that he has readied a virtual army of Dragon Men, each equal to the first in all ways but one. The army doesn’t live because Diablo’s mystic live-giving potions were lost in a whirlpool when he fought the Fantastic Four. And he needs Goliath’s help to speed up his work so he can build a new device.
Goliath angrily lifts Diablo up, demanding to know what he did to the Wasp. Diablo opens a computer screen, revealing the still-unconscious Wasp being guarded by the real, living Dragon Man. He says that, if Hank doesn’t put him down and do as told, Diablo will give his minion the order to destroy the woman he loves. Hank has no choice but to do so.
At their plane, the Avengers receive a call from Janet’s Avengers’ badge and see on their computer screen that she’s being guarded by Dragon Man. Thinking their location must be right below them, the Avengers decide to go for it. The plane lands, and Hercules offers to prove himself and to go rescue the Wasp alone. The Avengers aren’t sure of the idea but decide to give it a shot.
As Hercules continues to scout the big caves, the remaining Avengers go after Diablo himself. They notice the castle doesn’t look like the old one on their map, but don’t think it really matters. They get spotted and a blast fires, but everyone manages to dodge it. Hawkeye quickly releases one of his blast-arrows, and on impact on a wall of the castle makes an entrance which they all run through.
However, on that moment, Hawkeye gets knocked out by… Goliath?! He shouts that he has no choice but to defend Diablo, no matter what, because he can’t allow any harm to come to the Wasp. The Avengers don’t like fighting their own teammate, but do anyway though Hank manages to knock Quicksilver out as well.
Hercules notices lava around, which reminds him of the time he spent at Hades’ home. But Dragon Man ambushes him and gracefully flies in front of him, immediately knocking Hercules away! Luckily, he is unharmed and the battle continues. Hercules slams his fist against a wall, causing some loose stones to collapse on Dragon Man. Thinking he won, Hercules wants to continue his search, but with no such luck. Dragon Man gets up again and continues to fight Hercules.
Colonel Ling awakes the Black Widow after his attack on her using the Psychotron. Natasha fakes that she’s under her former boss’ influence again, and lies she’ll do whatever he tells her. He leaves her quarters, giving Natasha the perfect opportunity to escape. But, as she tries to find the exit of the large base, soldiers soon spot her. She uses her Widow-Bite to help her escape, and eventually manages to defeat most of the soldiers.
Unfortunately, Ling and Dr. Yen were observing the Widow at their personal office and Ling had already suspected their first test of the Psychotron had failed. He opens a big video screen behind the Widow, shouting at her that her attempts to escape have been discovered, making her realize this was all a trap. Sleeping gas appears, causing Natasha to fall asleep.
(Transylvania, Diablo’s castle)
Goliath continues to fight both Quicksilver and Hawkeye, despite their attempts to calm him down. Wanda shouts at Hank to stop it, explaining to him that Hercules is already trying to rescue Wasp, and Wanda has full confidence that the Prince of Power won’t fail. Hank agrees and decides to switch sides again, leading the Avengers to Diablo’s lab. However, Diablo had already monitored everything and steps out of the shadows, attacking Pietro with his Dyna-Disk. Diablo rushes to pull a switch to cause an explosion, which will make the caverns Hercules and the Wasp are in collapse entirely.
But on that very moment, Captain America returns! He uses his shield to push Diablo away from the control panels. Cap reveals that he was cleared of all charges about joining the Red Skull’s army and is now back in action, and had heard of Diablo’s plan. Diablo fakes defeat, but quickly gets up again and tries to strike Cap using his Dyna-Disk. Luckily, Cap already suspected such an attack and uses his shield again as defense, managing to knock the villain out permanently.
After a reunion with his teammates, Cap reveals he learned about their whereabouts, thanks to the group’s homing beam in all of their aero-cars. Hank is glad to see Cap again, but wants to go to the caverns now to rescue the Wasp.
Hercules gathers all of his strength, and manages to throw Dragon Man into the lava nearby them, earning his victory. Wasp wakes up and thanks Hercules for his help. The other Avengers rush inside, and Hank and Janet happily reunite. Seeing how happy they are makes Hawkeye wonder what happened to Natasha. Cap reminds the team they’ve still got the Dragon Men army to worry about, but he has already thought of a plan. Taking Diablo with them as their prisoner, the Avengers depart in their plane back home and make the entire castle explode!
After dropping Diablo off at the prison, the Avengers return back home. Hank receives a warning message that the Black Widow is a prisoner behind the Bamboo Curtain, and her captors have revealed to them that she was an undercover agent working for SHIELD. Cap defends that they have to immediately go rescue her, if that’s truly the case. Hawkeye angrily shouts that he is the man who loves Natasha, and that he’ll lead this mission.