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

The two sitcoms could hardly be more tonally different, but this week’s crossover episode of “Abbott” was relatively seamless.

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.