It was kind of a joke at first, that the two shows should cross over, he said.

On paper, it feels like theyd be a real tonal mishmash.

But then Rob and Charlie came to our writers room and we hashed out some real broad stroke ideas.

ABBOTT ELEMENTARY - Volunteers - Ava announces the school district is sending a group of volunteers to help out at Abbott; however, when they arrive, things dont go as planned. WEDNESDAY, JAN. 8 (8:30-9:02 p.m. EST) on ABC. (Disney/Gilles Mingasson) 
SHERYL LEE RALPH, CHARLIE DAY

Sheryl Lee Ralph and Charlie Day in the ‘Abbott Elementary’/‘It’s Always Sunny’ crossover episode.Disney/Gilles Mingasson

From there, we emailed back and forth beat sheets and then an outline.

They were super game for everything.