It might be always sunny in Philadelphia, but that doesn't mean there aren't some clouds about to hit Abbott Elementary school. A major crossover event kicks off on Wednesday's episode of Abbott Elementary,

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.

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.