The highly anticipated crossover episode of “Abbott Elementary” and “It’s Always Sunny in Philadelphia” blends the raunchy, NSFW style of the FX show with the witty, family-friendly romp.

Lisa Kudrow revealed during an interview on “The Drew Barrymore Show” (via People) that she recently discovered a note the late Matthew Perry left for her inside the “Friends” cookie jar, which he gifted her after they wrapped filming the series finale in January 2004. Kudrow wouldn’t reveal what the letter said but mused: “Timing …

The collaboration commences with Season 4, Episode 9, of "Abbott Elementary," airing Jan. 8, and will continue with a follow-up episode of "It's Always Sunny in Philadelphia," expected to air in the show's upcoming Season 17.