Cap finishes the tour around the Mansion he has given to new Avengers Quicksilver, Scarlet Witch and Hawkeye. Rick is present as well, but he doesn’t think it’s fair that these three newcomers are official members and that Cap thinks Rick isn’t suited to be one. Cap asks if there are any questions but, apparently, they’re none. Pietro smirks, and thinks to himself that it’ll only be a matter of time before he gets to be team leader, and Hawkeye thinks the same.
Seeing there are no questions, Cap wants to start their first mission: to find the Hulk. With Iron Man, Giant-Man, Thor and the Wasp now gone, Cap feels that the green goliath might provide them with the needed strength. Cap stops talking for a while, but notices that they all think he isn’t fit to be leader, because they think he’s too old. Cap notices it especially in Hawkeye’s eyes, a man who has never taken orders from anyone. Clint can’t stand it anymore, and says out loud that he wants to vote for a new leader. Cap stops him and makes it clear that Hawkeye will only get to speak like that when he has been on the team for as long as Cap has. He understands and backs off, saying he’s in no hurry and can wait. Wanda is impressed by Cap, and thinks she’ll like it there. Meanwhile, Cap whispers to Rick that he hopes he’ll be able to handle this young and ambitious team.
It doesn’t take long before word to go out, and reporters everywhere mention to the public that the Avengers are off to find the Hulk and make him the offer to rejoin the team. But, even as the speed proceeds with grim intensity, the Hulk himself is being whisked through the sky on a fantastic journey into captivity. Not realizing the fate of the Hulk, Captain America proceeds.
Cap leads the Avengers to another part of the Mansion, and has a treat for them. He explains that being on the team is more than signing out autographs, and leads the team into a large, vast chamber, the sight of which almost staggers the senses. Cap introduces the chamber as the Avengers’ “play room,” which has each conceivable electronic device installed with every kind of possible attack that might face the Avengers on a mission. This is where they train to master it. Pietro finds it obvious that only a man with the wealth of Tony Stark could have build this, and regrets that he doesn’t have any super powers. Wanda believes otherwise, and remembers Iron Man who is said to be in Stark’s employ, and suspects that Iron Man might be the power behind Stark.
Hawkeye gets even more impatient and wants to know what they are supposed to do. Cap promises that it’ll be worth the wait. A split-second later, a sizzling stun-ray shoots towards Hawkeye, but the amazing archer moves with the speed of thought, and quickly takes out on of his arrows to destroy the object. Cap is impressed. However, suddenly flamethrowers spit fire out of the walls! Clint doesn’t notice them, but a fast Quicksilver does. He runs towards the marksman, and pushes him down into safety before getting hit. Cap congratulates Pietro for succeeding in this test, the purpose of which was to see how fast he would help a teammate in need.
But the test isn’t over yet. Pietro moves deeper into the room, but has a hard time avoiding additional rays aiming at his head. Hawkeye notices it, and shoots arrow at the machines and destroys them. Cap really is impressed and thinks Hawkeye will be an Avenger to be proud of. Wanda isn’t too happy because Clint destroyed the machines before she had the chance to show her powers.
Suddenly, a giant, green robot smashes through the walls, and he has a message from his master for the Avengers, and it concerns the Hulk. The robot’s hand reaches out to Cap, and he warns the others to stay back. Cap quickly dodges the fist’s slam on the ground, and the others are impressed by his great speed and now respect him, even Hawkeye does. Cap tries to destroy the robot with his shield, but with no such luck. The other Avengers won’t stand to the sidelines any longer, fearing for Cap’s life and decide to go help him out.
Hawkeye shoots a blaster arrow, but it brings no harm to the robot. Pietro decides to grab a piece of steal nearby him to use it as a crowbar. Wanda is glad that she can finally help out, and decides to use her Hex power to slow the robot down for a while. The robot stumbles, which is just the chance Pietro needed. He runs fast onto the robot’s back, and opens its main control panel. Hawkeye gets the plan, and shoots a few arrows against the panel, and the explosion defeat the robot. Even though the robot’s demolished, his recording tape still runs and mentions to the Avengers that they will find the Hulk in the desert.
At the same time, leagues beneath the surface, the Mole Man hates to see his robot’s defeat, as he was certain it could destroy the Avengers now that Thor and Iron Man are gone. However, he doesn’t cry, because the Mole Man thinks he’ll get another chance since he lured the Avengers to the desert, and that they won’t be able to resist the bait he has in store for them. The Mole Man laughs, and orders his mindless subterranean slaves to prepare… the Minotaur!
The Avengers take off in their newest model-jet, and head towards the desert. They realize it could be a trap, but have no clue who could have forged it. Once having arrived, Cap decides to play on a hunch and head for the spot where the Hulk helped them defeat the Lava Men, hoping he might be there. They make it to the spot, and Cap decides to land the ship, before the nearby military base’s radar picks them up and sees them as enemies. A few minutes later, Pietro has used his speed to quickly search the entire area for the Hulk, but found no trace of him.
Little do the Avengers realize that, a few minutes earlier, on the mesa just beyond them, a silent airship has landed and entered a secret, camouflaged opening. The pilot is glad that it is safe and that no one will suspect that the Hulk is his prisoner. Again a few minutes later, the Hulk finally manages to break out of his prison, and battles his captors to a battle of life and death!
Cap realizes that he thought wrong, and wants to go back to the Mansion and search the robot for clues. Pietro asks to wait, as he has thought ahead and has brought a map of the area, and asks if he can perform a larger search. But, the Mole Man overhears them, and decides to start his plan. He pulls a switch on one of his machines, and the ground below the Avengers opens! They fall into a deep chasm, and don’t know what to do. Cap has another idea, and orders Hawkeye to use his suction-tipped arrow. Clint does, and a cable comes out of the arrow, and hacks onto the walls. Hawkeye grabs it, and is impressed by Cap’s quick thinking and leadership qualities.
The others grab the cable as well, and can now glide safe to the bottom. After landing, Pietro offers to go run ahead and see if there’s any danger. Wanda worries about her brother, but Hawkeye asks her to stop doing that or else she has joined the wrong team. A short time later, the Avengers hear Quicksilver screaming, as if he were in shock. He makes it back to the heroes, and can’t believe the horrible thing he just saw. The others ask him what it is, but he isn’t sure. Suddenly, they can all hear loud footsteps coming towards them. Cap warns them to stay back, as he wants to face their enemy first. Cap moves closer, and confronts… the Minotaur!
The giant beast throws rocks at Cap, who covers his face using his shield. Cap recognizes the creature as the most dreaded of Greek mythology, and remembers that it’s a half-man, half-bull trapped under the earth, waiting for its human victims. Wanda rather wonders how they can defeat it. Cap speeches the same way as the Avengers always do: with courage, skill and the words of… Avengers Assemble!
Cap throws his shield at the creature’s head again, but it has no effect. Hawkeye warns Cap that they are supposed to be a team, and he decides to fire his blast arrow. The arrow hits the Minotaur, and he gets covered up in smoke. Hawkeye is confident that he has defeated their enemy, and brags about it to Wanda. However, she notices that it’s still alive and grabs for Hawkeye. She screams, and Hawkeye quickly dodges before being caught. Cap warns everyone to head towards the end of the tunnel, hoping they’ll be safe there. Pietro runs so fast that he makes it first out but, when the Minotaur slams against the walls again, bricks fall down and destroy the entrance! Cap pushes his friends to safety, but Wanda worries about Pietro, who is already inside.
Luckily, Quicksilver was too fast for the rocks to hit him, and is unharmed. However, he also worries about his teammates, but at least finally understands why Cap finds the Hulk’s strength to be needed. The Hulk himself is almost out of the ship, and not even Battleship Steel can stop him. Pietro decides to best start dig himself out. However, he hears noises behind him, and gets attacked by the Mole Man’s creatures. Pietro defends himself by running around them and hitting them at the same time, but one unseen creature fires gas at the speedster, which knocks him out.
The creatures capture Quicksilver, and bring him to their leader. The Mole Man demands to know the secret behind Pietro’s speed, but he doesn’t even want to tell, even should there be one. However, Pietro mentions that he has studied the Avengers’ case histories, and recognizes the Mole Man and is aware that he one day would like to rule the surface world. The Mole Man orders his slaves to bring Pietro to the dungeon, and is certain that he’ll talk when the Minotaur kills his friends. Pietro realizes that the Mole Man is behind this mess, and hopes that the others will be safe.
The Avengers have made a narrow crevice, but realize it won’t be enough for Quicksilver to go through, unaware that he’s been caught. They hear the Minotaur approach them, and Cap orders Hawkeye to shoot his flare arrow against the monster. He does and, on impact, the Minotaur screams. Cap explains that the monster has lived in the darkness for ages, and the sudden sight of light hurts him. Cap throws away his shield again, but this time not at the monster, but at the rocky wall behind him.
Rocks fall onto the Minotaur, which gets angry. Cap grabs his shield back and, when the Minotaur uses his head trying to butt Cap – he knew this would happen – he is unharmed. Wanda uses her Hex power, and the whole wall falls forward, locking around the Minotaur’s horns! The Avengers realize even if the Minotaur is able to free himself, the horns will most definitely break off since they are stuck so deep, and since they are aware he can’t live without them, he’ll soon die.
Meanwhile, the Mole Man has trapped Quicksilver in a strange holding machine. Pietro orders him to stop now, or else the Avengers will never stop hunting him down should the Mole Man kill him. Pietro doesn’t really care, as he isn’t afraid to die, but warns the Mole Man to remember the Avengers’ history, as they have never been defeated yet. The Mole Man laughs, since he is aware that Pietro is speaking of the old Avengers team and he isn’t so sure the same counts for the new one. He gives Pietro once last chance to tell him how to get the same speed he has, or else.
Pietro remembers Magneto, and that he also seemed to talk like an old movie villain. Mole Man hates being mocked, and decides to activate his machine to make Pietro pay. He explains to Quicksilver that he shall now be subjected to ultrasonic vibro waves! And within minutes, Pietro’s muscles will be reduced like mashed potatoes! Pietro mocks that he’ll be glad to just not hear the Mole Man’s awful voice and swears that, even though he hasn’t been an Avenger for that long, will never disgrace their name by betraying them.
The Avengers rush in, and are glad to find Pietro still alive. Hawkeye shoots some well-placed arrows against the holding machine, and releases Pietro. He notices the Mole Man escaping, and warns his friends to do something about it. Wanda first destroys the machine with her powers so it can’t do any more harm in the future. Wanda hugs her beloved brother and informs him that, under the leadership of Captain America, they’ve defeated the Minotaur and found him as well. Pietro admits he already expected that, and is glad to be officially on the team now.
Cap throws his shield and Hawkeye fires another stun-blast arrow against the Mole Man, who had almost gotten out. He tries to send his mole creatures out, but they have already been defeated by the shield and arrow’s impact. Mole Man is aware that he’s almost defeated, and hates to go to his last resort plan. He pushes a button, and a thick glass comes out of the floor, trapping the Avengers inside it!
Then, a blinding flash surrounds the chamber, and the Avengers are send back to the surface! Hawkeye, Quicksilver and Scarlet Witch are glad that they’ve won, and have gotten their baptism in battle. However, they don’t feel well about failing the Hulk. They rush back to their jet and leave, and Cap tells them to look at the bright side: they have found their own strength now, and proven that they can work as a team and won’t need anyone to help them. They cheer, and are with full confidence that they can handle anything now.
However, the Avengers are unaware that, not far from them, an unconscious Bruce Banner is found by soldiers, and they believe that he is… dying! They can’t even feel his pulse.
The Avengers return to their Mansion, and Cap notices how friendly Pietro, Wanda and Clint now act towards them, but wonders in himself if he has now truly found their trust, or if they will soon fall back into their former bickering. Only time will tell.