In the study group's first year at Greendale, Troy and Abed were lab partners in a science class together. As part of an assignment they were given a mouse to experiment on. Naming him Fievel their first lab assignment was to teach him to to respond to a particular song. Unlike the other students, the song they chose was a duet named "Somewhere Out There", the theme song from an "An American Tail". Troy's fear of rodents kept him from bonding with the mouse as Abed had. He accidentally backed into another classmate who was handling her mouse. Frightened by the rodent, he ends up knocking over Fievel's cage and the mouse is set free. Due to Fievel being on the loose an exterminator was called in to deal with the problem the following day.
Wanting to save Fievel, Abed tries to get Troy to assist him with looking for the mouse before then but he is uninterested. Abed then questions if they are even friends since he is unwilling to help out and runs off singing "Somewhere Out There". Later, Abed finds the mouse in the entrance of a hallway air vent. He starts to sing the song but Fievel is unresponsive. Troy then unexpectedly shows up and sings "Somewhere out There" in a duet with Abed which starts to have an effect on the mouse. As they finish the song, Fievel leaves the air vent and runs up Troy's pant leg. Screaming loudly, Troy rushes to the lab with Fievel in his pants and he and Abed quickly secure him in a cage muttering how disgusting that was. Abed then sincerely thanks Troy for his efforts ("Environmental Science").