Disclaimer: Look, if I owned this stuff, I wouldn't be submitting it to a fanfiction site.
"If you're happy and you know it, clap your hands!"
"Guiteau."
"If you're happy and you know it, clap your hands!"
"Guiteau!"
"If you're happy and you know it, and you really want to show it!"
"GUITEAU!"
"If you're happy and you know it, clap your hands!"
"Shut up!"
Guiteau grinned and nudged Czolgosz with his elbow. "Sounds like you're not very happy."
"I am trying to concentrate."
Guiteau frowned. "On what?"
"Thoughts."
"Well, stop that. I'm sure they're very depressing. Look on the bright side, Leon!"
"For you, it is Czolgosz."
"Don't be that way, Leon."
"Czolgosz."
Booth slammed his hands on the console. "Both of you stop bickering or I will turn this time machine around!"
Guiteau stuck his tongue out at Booth's back. Czolgosz smiled very slightly and went back to his thoughts.
Booth sighed, "Thank you."
Guiteau cleared his throat and grinned once more. "The wheels on the bus go 'round and 'round!"