The next day Princess Bubblegum and Prince Gumball were waiting for Marceline in PB's lab.
"Where is she?" Gumball wondered impatiently.
"She's coming," Bubblegum assured, "calm down."
"I'm tired of being a rodent!" Gumball said.
Bubblegum picked him up off the lab table.
"And can we move to a different room?" Gumball requested, "I don't trust that rat." referring to Science the rat, who was watching intently from her cage.
"Yeah, alright." PB said.
They went to the main hall.
Eventually, Marceline arrived.
"I'm here..." she said.
"Change me back, NOW!" Gumball uttered.
"Hold on, more news." Marceline replied.
"Grod! Why?" PG whined.
"Here it is," Marceline explained, "you are getting turned back right now, see the reversal isn't a potion, it's a regular spell."
"Okay." Gumball said.
"Yeah, and it's a spell that I can't exactly do yet." Marceline continued.
"...Uh, 'kay?" Gumball replied.
"So I had to get the only person around that we know who can do the spell." Marceline informed.
"...Huh?" Gumball said in response.
It was then Marshall Lee came in.
"'Sup, Pink Mess?" he said.
"Oh...man." PG said, mortified.
"Come here." Marshall instructed.
He took rat PG.
"Ha ha," the vampire bantered, "oh, isn't he precious."
Marshall started poking Gumball's rat head.
"Eh! Stop it." PG whined.
"Ha ha ha," Marshall laughed, "talk about a memorable day."
"Come on man, it's been excrutiating enough living as a rat," Gumball begged, "please, just change me back."
"Okay." Marshall said.
He tossed PG in the air.
"Ad normalis." Marshall stated.
With that, Gumball turned back to normal.
"Oh! Yes!" he said happily, "I'm not a rat anymore!"
"Yay!" PB said, gladly squeezing the prince.
"This situation does not leave this castle!" Gumball said firmly.
"A little late for that," Marshall Lee informed, "Mo-Chro's been telling everyone."
"Mo-Chro?" Gumball responded, "That traitor, I had to do him a disturbing favor."
"Oh well," Marshall Lee said, "my work here is done, come on Marceline, let's go take out that raccoon hiding under my house."
Then they left.
Bubblegum and Gumball stood there for several seconds.
"I'm never testing anything for you ever again." PG said dryly.
"'Kay." Bubblegum said.
She kissed his face.
"...Love you." she said playfully.
"Meh...ditto." Gumball muttered.
There, once again, not the greatest thing I have ever written, but...I wrote it anyway.
Ad normalis, according to the questionable Google Translator, supposedly means "To Normal, or Back to Normal" in Latin, though I'm not 100% sure.