Katy Perry continued to sing as Elmo began to melt and melt. Though no one was really noticing this as everyone's attention had been focused on the Twelfth Doctor.

The Tenth Doctor looked up and cried

"I don't wanna go"

"Well too bad" The Twelfth Doctor said.

The two Doctor's began having a dance battle.

Katy Perry changed her attention to The Doctor and continued singing

"You change your mind..."

All of a sudden Elmo cried out in a huge merciful way.

"KATY!"

This startled everyone and Boo started crying, Jesus cursed under his breath. "Oh my Father"

... Katy Perry looked at Elmo and said

"Elmo, I thought you wanted to play dress ups."

Elmo looked at Kate quizzingly before addressing everyone else.

"Elmo is playing Miss Katy, Elmo's playing homicidal maniac."

Everyone started to laugh at this surprising turn of events and kept Elmo distracted until he was arrested (there was a police box nearby)... for being a homicidal maniac.