She looks exactly the same as the main timeline Gwen at age of 10 except she has the Omnitrix.
As Ben wakes up inside the Rust Bucket, it seems that they are stopped at a gas station. Outside, as Gwen drinks, criminals with masks come out of the gas mart. One of them removes their mask and before they're ready to leave, Ben appears out of nowhere. Max tells him to get back inside the RV, but Ben's courage comes from the Omnitrix. Somehow, when he was ready to activate the Omnitrix, it wasn't there. Then pages of comic strips pass while a narrator explains that stories are not always told once and that in this case, it will be told another way. As it returns to Ben, he finds that he’s in trouble.
The biker robbers are ready to attack Ben and Max orders him not to stand around to be vulnerable. Max knocks one of them down by whipping him off his bike with the gasoline hose. The second one comes, and this time, Max uses a garbage bin to knock him down. They finish them off, but as they're ready to leave, Ben asks where the watch went. It seems that Max has no memory of a watch. They drive off and the police come to take the criminals.
In the RV, Gwen praises Max for what he did earlier. Ben, however, worries where the Omnitrix went. When he asks Max, he says he picked up Ben a few hours ago and he wasn't wearing a watch. Gwen offers help to look for the Omnitrix and asks what it looks like. Ben tells her that she’s seen it for so many times. She also says that it's their first day together for summer. When Ben mentions their recent fight with Vilgax, Max immediately loses control of the RV, but regains control, saying he dodged a skunk. It seems that Max has no memory of the event either.
In space, Vilgax’s ship pursues a smaller bluish vessel, which holds the Omnitrix. Inside the ship, a robotic lieutenant reports that their ship is losing power. Vilgax orders them to find as much power as possible to get the Omnitrix in his hands. As Vilgax’s ship shoots a powerful blast, they successfully disable the smaller vessels propulsion system. As they were ready to board, the small ship self-destructs and Vilgax is protected from the blast. The ship then launches the container with the Omnitrix to Earth.
In the RV, Ben continues to explain who Vilgax was to Gwen. Max wonders if it wasn’t a movie Ben saw. Ben tries to get them to believe his story, yet Gwen gives a good point why they should after telling them he saw Bigfoot at a family picnic.
They arrive at their campsite and Gwen seems to enjoy the spot. But Ben comes out and realizes that he’s gone back in time and they're at the same area he found the Omnitrix. He insists that if he found it in the woods, everything will be normal again. Gwen doesn’t seem to think that Ben is normal anyway. Ben asks Max if he believes everything he’s said, though he still seems ignorant about it.
As Ben helps Max out to put up the tent, Ben notices the shooting star which holds the Omnitrix. As he runs to the impact site, he finds the pod that held the device gone. It seems that Gwen got there before him. As she tries to get the Omnitrix off, Ben insists for her to give it back. In an unexpected event, she activates the Omnitrix and transforms into a femaleHeatblast. Ben tells Heatblast to be careful not to put the forest on fire, but she said that only an idiot would do that. Heatblast experiments with her powers and she uses her fire power to spell Gwen with fire in the sky. Ben asks how she did that, especially after how Ben as Heatblast took a while to learn such a technique. Heatblast then asks if she can turn into any other alien, but Ben seems to have something in mind.
In space, a pod has been released from Vilgax’s ship and is headed down to Earth. Meanwhile, Ben seems to have fun with Gwen, having transformed her into Grey Matter. As the raccoon chases Grey Matter, Ben laughs at Grey Matter's attempt in running away from it. Ben then grabs her to tell her who knows how the Omnitrix works. Suddenly, the same pod that was sent out by Vilgax arrives on Earth, but lands where Ben and Gwen were. It transforms into a giant robot droid and it seems to be looking for the Omnitrix.
At a nearby campground, the droid attacks the area to flush out the holder of the Omnitrix. Diamondheadcomes and it seems that she's not good at it. Ben gives her a tip and tells her to slice it and dice it. While she fights the giant robot, Max tells Ben that he’s in danger and needs to get him and the others to safety. Max thinks that Gwen is doing pretty good in combat and she's a quick thinker. Compared to Ben, she's more strategic. While she reflects a giant blast back to the droid, it completely destroys it. Back at Vilgax’s ship, Vilgax finds that his droid is completely destroyed and infers that the holder of the Omnitrix must be cunning and strong.
Back at the RV’s camping site, Ben is awakened by Max’s snoring and Gwen is outside. She says that she didn't sleep the whole night and she is having fun experimenting with the Omnitrix. First, she transformed intoUpgrade to increase the processing power of her laptop. Then, into Ripjaws to catch fish. After that, she turned into XLR8 to return home and pick up some clothes she forgot. Ben tells her that the Omnitrix is a device not to be used for fun, though she proves him wrong by bowling with Four Arms. With every throw, she makes a strike and Ben is surprised by her talents.
Back at Vilgax’s ship, a nearby monitor comes up in front of him to show him where the Omnitrix most likely is. He seems to be heading to the location. At the bowling alley, Ben seems to be disappointed how everything is turning out so far and it seems that Gwen is doing better than him. But before they do anything else, Vilgax arrives in a giant ball. Gwen tries to reactivate the Omnitrix, but no luck. It needs to recharge. Vilgax then takes Gwen away to try and remove the Omnitrix. Max arrives and picks up Ben from the severely damaged bowling alley.
In the RV, Max comes to chase down Vilgax. It seems that he still doesn't have any memory of their last encounter after Ben destroys Vilgax, though he seems to believe his story. Meanwhile, at Vilgax’s ship, he prepares to remove the Omnitrix from Gwen. She insists that he should remove it by simply slipping it off, though Vilgax wants to have a little fun while removing it. As the RV drives through the path that the giant ball made, Max opens a compartment where a small handgun is kept. He gives it to Ben, just in case.
As they arrive at Vilgax’s ship, Vilgax is ready to remove the Omnitrix. Max shoots his weapon, though he dodges the blast. Vilgax then slices the weapon in half. While Max and Vilgax fight each other, Ben comes up to Gwen to help her out. Ben then grabs the weapon and blasts Vilgax, but after that, a great surge hits Gwen and it somehow removes the Omnitrix. Ben is about to grab it, but it end up on Max instead. So to finish things off, Ben tells Max to transform to Upgrade and merge with the RV to make some modifications.
Vilgax is able to hang onto the RV after they ram him, though Upgrade pops a hand out from the side and throws him in the air. Ben then uses the blaster to send him back to his ship, and they seemingly end Vilgax's life, as well as destroy his ship. The episode ends and the narrator says that some stories can be retold differently and you may never know how it'll turn out.
- Grey Matter
- Four Arms
- Gwen 10 (first appearance)