The star of the FX series also admits he was initially hesitant about the crossover concept as 'It's Always Sunny in Philadelphia' heads into its 17th season.

A crossover television event is always a thrilling prospect—not one, but two of your favorite shows coming together as one? There have been plenty of surprising combinations throughout the years: The Jetsons met The Flinstones,

Two comedy forces collided this week on Abbott Elementary, as the school staff welcomed the Paddy’s Pub gang from FXX’s It’s Always Sunny in Philadelphia. Did the crossover episode make the grade, though?

This week's "Abbott Elementary" episode is just half of the story. "Volunteers" featured the long-awaited crossover with FX's long-running "It's Always Sunny in Philadelphia," as told from the vantage point of the hit ABC sitcom.

Charlie learns to read, Dee impersonates Ben Franklin, and Frank fights raccoons. We don't quite know what's up with Dennis though.

A new “Abbott Elementary” episode brings volunteers from “It’s Always Sunny in Philadelphia.” The crossover episode airs Wednesday, Jan. 8, at 8:30 p.m. ET on ABC.

Here's a look at our real-time thoughts on tonight's crossover between FXX's It's Always Sunny in Philadelphia and ABC's Abbott Elementary.

A live TV streaming service that includes ABC in its channel lineup will do the trick. Hulu Plus Live TV and YouTube TV are among the options -- both start at $83 per month -- and you can stream the Abbott Elementary episode with Sling Blue if you're in a select city.

"Abbott Elementary" star Janelle James is schooling us on that "It's Always Sunny" crossover and unwinding with the help of "rich people" wellness.