After much anticipation, the unlikely meeting of the two worlds unfolded on Wednesday's installment of "Abbott Elementary." ...

As of Jan. 9, the episode is available to stream on Hulu. The second crossover is expected to be an episode of "It's Always Sunny in Philadelphia," which has aired on FXX since 2013.

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

Here's some background and inside jokes to help fill in some of the gaps for viewers who don't watch both Philly-based shows.

The star of the FX series also admits he was initially hesitant about the crossover concept as 'It's Always Sunny in ...

The Abbott Elementary & It's Always Sunny In Philadelphia crossover had hilarious character interactions, but it hid callbacks in its witty writing.

Of course, Abbott almost definitely would have been renewed regardless of Always Sunny‘s influence. This isn’t the first ...

In true Abbott Elementary fashion, “Testing” was full of shenanigans. Janine found herself reeling after her second graders ...

With the first part of 'Abbott Elementary' and 'It's Always Sunny in Philadelphia's crossover airing Wednesday on ABC, ...

Spoilers for the Abbott Elementary and It’s Always Sunny in Philadelphia crossover are ahead! If you haven’t watched the first half of this event yet, you can stream the Abbott episode with a Hulu ...

The "It's Always Sunny in Philadelphia" crew is headed to "Abbott Elementary" in the first of two crossover episodes. The highly anticipated crossover episode will see Charlie (Charlie Day), Mac (Rob ...

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.