The episode starts out in space near Vilgax's ship. Within the ship, spotlights highlight three different armored mercenaries. The first is Sixsix, who wears purple armor covered with many pockets encasing various weapons, and has a jet-pack on his back. Next is Kraab, a crustacean-like hunter with gold armor. And as his name states, he has a sideways mouth, four-scythe-like legs, and a large, powerful pincher on his left hand. Last is Tetrax, who is listed in the credits as Hoverboard. He has a suit of seemingly impenetrable gray armor. He carries a rifle, and a green hoverboard. He is the most mysterious of the three. Vilgax's voice comes over in an intercom, announcing the start of their audition. A swarm of robot drones come in to start the fight. First up is Sixsix. With the many weapons in his suit, he makes the short work of most of the robot drones. Kraab then joins the fray next, using his powerful left pincher to dispose the last of them. Then the same robot droid that Ben had fought before shows up. Tetrax however is the next to fight this one, flying right towards it without thinking about his safety. The robot blasts him, but he is merely affected by it. Tetrax then smashes through the droid in a single blow. With Vilgax impressed, he offers a reward to the first hunter that retrieves the Omnitrix. He then sends them out to the planet Earth.
In the middle of the desert, Grandpa Max has set up on what seems to be an obstacle course for Ben. He completes the final touches, and Ben transforms to Diamond Head. He tells Diamond Head to think before he should act, and should use some strategy to defeat his opponents. But Ben is unconcerned that brute force is a lot stronger, and more fun. Grandpa Max starts up the course, and Ben starts with some target practice with various cans and targets that pop out. Meanwhile, Gwen is by the RV, sunbathing and applying sunscreen. She calls Ben a show-off. Grandpa Max tells Diamond Head to focus carefully, and continued with the training. Ben feels overconfident by now, which led him to one of the traps set up by Grandpa Max. A tire swing hits him, and throws him off balance, and causes him to fire diamond shards in every direction. Grandpa Max and Gwen were nearly hit, but managed to dodge them. Unfortunately for Gwen, a shard hits her sunscreen, causing it to pour down her head. Diamond Head apologizes for the incident.
In the RV, Gwen continues to chide Ben for nearly turning them into Swiss cheese with his stray shots. He continues to plead for an apology, wondering what else Grandpa Max and Gwen want from him. Grandpa Max eventually answers that Ben should use the Omnitrix more carefully, strategically, and more seriously. Ben does point out that he has defeated quite a number of villains by this point, so he must be doing something right. Gwen then claims that he will screw up one of these times and be beaten, and she hopes to see that to occur. Ben doesn't believe her of course. Then suddenly, the RV sputters and breaks down.
Back at the obstacle course, the three bounty hunters have successfully traced where the Omnitrix was first activated. They explore the location, and Tetrax notices a can with a diamond shard on it. Sixsix flies up and takes it with a retractable hook, only to have it ripped off by Tetrax. They both have a short standoff, eventually resulting with Sixsix backing down and taunted him in a foreign alien language. He then flies off. Kraab then follows, using his four legs to burrow through the sand. Tetrax then leaves the area, triggering one of Grandpa Max's traps. In an instant, he fires the targets with his rifle, which also destroyed the whole course as well. He rides his hoverboard and drops the can with the shard behind.
Ben, Gwen, and Grandpa Max find themselves at an abandoned mining town, called Slaterville. According to Gwen's IntelliMap program on her notebook, it was a town incorporated in the year 1857, after the discovery of silver. It was abandoned after the mine ran out roughly a decade later. Back at the RV, Grandpa Max detects the cause of their breakdown. It seems that one of Ben's stray shards hit the fuel line. Ben suggests for his help by becoming into an alien, but he insists on doing it himself. With absolutely nothing to do, he decides to check the town out himself. Grandpa Max has Gwen follow him so he doesn't get into any trouble.
In town, Ben enters an old, abandoned equipment storage building. Gwen calls out to him. Ben then sees an opportunity to prank her. He starts by hiding in the shadows, and uses the Omnitrix to transform to Ghostfreak. While she searches, Ghostfreak passes through her and makes her chill. Ben is amused by his own prank, getting a good laugh as Gwen pretends that he does not scare her. Just then, the ground is pushed up from something burrowing under it. Ben drags Gwen out of the way, and Kraab shows up. Ghostfreak and Kraab confront each other, and insults Kraab of his appearance. He ignores the comment and tells Ben to hand over the Omnitrix. Ghostfreak refuses, and moves his eyes onto his back to ask Gwen what Kraab wants. She obviously points out to him that he wants the watch. He explains to Kraab that it is stuck on his wrist, but he didn't care. He was hit a few times, and eventually turned invisible.
With Ben invisible, Kraab seems to be at a great disadvantage. Unfortunately, Ben's attempt to sneak behind him causes Kraab to spray an orange substance, which made his invisibility and intangibility useless. Kraab continues to thrash Ghostfreak around, and Gwen takes back the comment about wanting to see Ben lose a fight. Ben continues the fight, doing just as badly, and end up being blasted into a wall near a car lift. Kraab moves in for the kill, Gwen points out that the lever near him will activate the lift. Ghostfreak activates it and Kraab gets pinned to the ceiling. Ben then reverts back to a human again after doing so. They flee the scene, and Tetrax is seen watching from the rafters.
At the RV, Ben and Gwen detail the short battle against Kraab to Grandpa Max. Ben still wants to fight back, suggesting that he can turn into Four Arms and turn the crustacean-like hunter into a seafood special, despite the Omnitrix's obvious lack of power. Grandpa Max says there's no time, having completed repairs to the RV. Ben is disappointed as they flee the scene and continue on the road.
On the road, Gwen is on the lookout for Kraab. Ben comments that Kraab won't show up if he knows what's good for him. Kraab doesn't show up, but Sixsix does, cutting a hole in the roof of the RV to get to them. As Sixsix tries to grab Ben, Grandpa Max brakes hard, sending the hunter flying in front of the car. Grandpa Max then tries to run him down. It seems like the attempt works at first, but the RV stops shortly after. They take a quick look outside shows that all the tires have been severely popped. Sixsix is still on the road, uninjured from the earlier attack. As Ben, Gwen, and Grandpa Max flee to a nearby mine, Kraab burrows his way next to Sixsix and attacks him.
Inside the mine, Kraab once again confronts Ben and demands the Omnitrix from him. As he advanced, Grandpa Max steps between them and tossed a nearby chunk of metal at Kraab. His powerful pincer reduces the would-be projectile to shrapnel. Seeing this, the trio runs for their lives with Kraab in hot pursuit. They eventually end up at the center of the mine. With a large canyon in-between them and safety, Gwen asks what they're going to do. Grandpa Max finds a nearby lift and puts the kids in it. He then activates it and jumps into it, just barely reaching it before it's out of range. As it takes them across the canyon, Kraab prepares to cut the wire holding it up. He is stopped by Sixsix, who blasts him and then turns on the lift. As Sixsix pursues them, Grandpa Max comments that they need a plan. With the Omnitrix recharged, Ben decides to forgo the plan in favor of brute force. Grandpa Max points out that that is exactly what the hunters want.
Ben transforms himself into Diamond Head and goes on the attack. He plunges off the car and grabs on Sixsix, and the two plummet into the crater below. They then fly back out under Sixsix's power. As the lift takes Gwen and Grandpa Max to safety, Diamond Head stays behind to deal with the hunters. The action does not go as planned, though. Kraab shows up to join the fight, and Diamond Head turns out to be no match for the two experienced hunters. After knocking Diamond Head out, the two begin to argue over who gets the reward. As the do, a metal ball is tossed beside them. As they stare at it, it releases a gas that renders them unconscious. Tetrax then shows up, dragging the unconscious Diamond Head out of the mine and back into town.
In town, Tetrax tosses Diamond Head into some nearby crates, waking him up. With Diamond Head awake, Tetrax begins to complain about the Omnitrix winding up on a foolhardy youth when there are billions of other people it could have been found by. Diamond Head explains that it won't come off. Tetrax then explains that the Omnitrix uses alien DNA that binds to the genetic structure of the host, which is why it doesn't come off. As he does, Diamond Head tries to attack him. Tetrax easily dodges the attack and sends Diamond Head flying. As the two continue to fight, Tetrax berates Diamond Head on his lack of strategy, all the while dodging every attack. During the extremely one-sided fight, he points out that Diamond Head would have been killed were it not for him, and that an experienced fighter should have defeated the hunters without a problem.
After Diamond Head finally gives up, Tetrax explains that the Omnitrix is the most powerful weapon in the universe and is the key to an epic battle between good and evil. Diamond Head asks what side Tetrax is on, to which he replies by pointing out that Diamond Head isn't dead yet. He then says that his mission is to retrieve the Omnitrix. With it attached to Ben, he simply plans to take him with him so it can be removed. Diamond Head refuses to go, but Tetrax says that he doesn't have a choice. Diamond Head tackles him, saying that it is not, and gets tossed off just as quickly. Tetrax then starts to point out Ben's inexperience with his current alien form, not even realizing the true strengths and weaknesses it possesses. Diamond Head wonders what makes him such an expert. Tetrax says nothing, but instead takes off his helmet, showing that he comes from the same race as Diamond Head. When Diamond Head points this out, Tetrax says that he's a great warrior while Ben is merely an impulsive annoyance. Ben reverts back to human form after this and Tetrax grabs him. As he searches for his hoverboard, Kraab walks up holding it, having heard the whole exchange. Sixsix follows, carrying both Gwen and Grandpa Max.
Outnumbered two to one, Tetrax flees with Ben still in hand. Kraab fires at him, but his blasts are absorbed by Tetrax's armor. He eventually runs into a nearby house. Ben wants to help his family, but Tetrax points out that he would be quickly overpowered and captured. He then leaves Ben behind and goes to retrieve his hoverboard. Outside, Tetrax uses a barrage of shards to free Gwen and Grandpa Max. He then dives at Kraab, taking his hoverboard back from the hunter. After a quick flight away from the pair, he dives down and lands on Sixsix. Gwen and Grandpa Max take cover as this happens. As Tetrax and Sixsix fight, Ben finds that the Omnitrix has recharged. Kraab notices this, and follows him inside the house. Hiding behind a table, Ben gets ready to transform. He then hesitates, remembering the advice that both Grandpa Max and Tetrax had given him. He eventually settles on one and transforms. Kraab crushes the table, only to find nothing there. In the rafters, Grey Matter is seen sneaking about. He jumps onto Kraab, searching for a nerve cluster in the hunter's armor. He finds it and rips it out, causing the hunter's armor to go haywire and shut down.
Elsewhere, Tetrax and Sixsix are still fighting. Sixsix eventually gains the upper hand on Tetrax. Seeing Grey Matter draws his attention, and he attempts to fire a missile at the tiny figure. Grandpa Max hops on his back to stop him. Sixsix throws him off and prepares to slice through his attacker with a buzz saw. This provides enough of a distraction for Grey Matter to hop on his back. Tetrax complains about the interference, but Grey Matter ignores him and starts pulling nerve clusters in Sixsix's armor, resulting in the same haywire behavior as Kraab. Sixsix's jet-pack fires and takes the two on a short ride, crashing through the supports for a water tower in the process. Sixsix's armor then shuts down and lands near Kraab, giving Grey Matter just enough time to move out of the way of the falling water tower. Kraab comments on his hatred for the planet before getting crushed.
With the hunters defeated, Tetrax takes out a small cube and tosses it at them. The cube expands and covers them, then contracts, shrinking the hunters along with it. Grey Matter reverts back to human form as Tetrax pockets the cube. He promises to come back soon. When Ben points out the Omnitrix, Tetrax says that it's in good hands. He then gives Ben his hoverboard as a gift. Ben is confused, thinking that he needs it to get home. Tetrax says it was selective disinformation, which Gwen translates for Ben as "lies." Tetrax then activates a teleporter and disappears. Once he's gone, Gwen asks Ben why he gets all the cool alien stuff. Ben says it fits his personality Gwen sarcastically agrees, and then covers Ben's head in sunscreen, saying that they don't want his big head to get sunburned.
On Vilgax's ship, Vilgax watches as Tetrax leaves. He's more than annoyed at the betrayal. His subordinate confirms that the mercenaries do not have the Omnitrix. Vilgax figures that whoever possesses the Omnitrix must be as clever as it is fierce, but is not deterred. He insists that he will not be denied. The episode ends on that note.