|“||OVERWRITE. The power to completely change a timeline...the reality itself of a alternate universe...t-that's how it will work with my future experiment.||„|
|~ XGaster in regards to the Overwrite power|
Underverse 0.3 is the fifth episode of Underverse, and is currently the longest episode of the series so far. Cross!Chara attempts to take over Cross's body for the intentions of getting a human soul, but he's stopped by Cross himself. Once he's taken to Underswap, he realized that the coding sounded too familiar to him, and continue onwards to work for Nightmare!Sans. But, thanks to some advice, Sans and Underfell!Sans takes him down easily. Unfortunately for them, Cross!Chara get his wish after all, and now as X-Event!Chara does he get to mess with them.
Like before, Stereohead Studios provided the music for Part 1, and NyxTheShield took operations for Part 2; Strelok also sounded the second part and the revamped version of Part 1, released in May 22, 2018.
Furious over Cross' failure in Underfell, Cross!Chara attempts to take over, but he's knocked out before he could. Nightmare scolds Cross of what he's doing, but after Cross tells him his ambitions, he calms down, and takes Cross to Underswap.
Underswap!Papyrus mistakes him for his brother, and shows his new visitor to everyone, but considering that the code reminded too much of his, he goes ahead with Nightmare's plan. Fortunately, Sans and Underfell!Sans were able to distract Cross before he could do much to Underswap, but the huge victory ends up being a flop, as Cross!Chara is revived by the soul of Underswap!Chara.
X-Event!Chara throws Sans and Underfell!Sans out to the X-Tale universe, and Nightmare ties Ink!Sans up before X-Event!Chara begins his X-Event on the Underswap universe. He then performs a series of events on the Underswap crew thanks to the power of overwriting, evening using the cast to fight Ink over a white vial, before brawling with Underswap!Sans. Nightmare, at first, doesn't appreciate this, but over time, he felt confident that X-Event!Chara was much understanding than Cross, and allowed him to kill someone.
Meanwhile, Sans and Underfell!Sans tries to hide from the now captured Underswap characters, and Dream!Sans tells them that they should lower their negative feelings, as his brother feeds on it. After Underswap!Papyrus tells his brother that this was the best timeline they could ever live in, the three were able to enter, and Sans was able to stop X-Event!Chara thanks to his ketchup bottle.
X-Event!Chara soon tries to reason with Sans about his own timeline, and his purpose, but with the failure of his chance at killing, Nightmare kills Underswap!Chara, and leaves with X-Event!Chara, telling Sans to "spend his last moments".
Dream!Sans tells them all to head to Outertale, another safe pacifist AU, but Underswap!Papyrus decides to stay in the AU, suggesting that he has no chance at trusting Ink after the incident that has occurred. And as the crew heads to Outertale, Underswap!Papyrus looks up to the sunset, knowing that he and the rest of his timeline will soon vanish.
- Nightmare's font is changed to Haunt AOE in this episode when counting the non-revamped versions previously.
- During the fight between Ink!Sans, Underswap!Sans, and X-Event!Chara in part 2, there are three messages written in the wingdings font that appear throughout the battle: YOUR CREATIVITY IS A SHAME; YOU DONT DESERVE THE GIFT OF CREATING; YOU ONLY HAVE THE GIFT TO KNOW THAT YOUR USELESS LIFE IS NOT GOING TO END WELL.
- When Underswap!Sans fires his blaster at X-Event!Chara, the music is glitched out until Underswap!Papyrus starts running towards X-Event!Chara to prevent him to attacking him, as that would harm Underswap!Chara too