His character's latest evidence of stomach-churning debauchery occurs during the FXX comedy's first big Season 18 trailer, as seen above, and if the implications are correct (not those, Dennis), Frank is totally making out with a dead body. Before we even talk generally about Season 18 hitting the 2026 TV schedule or get into any of the trailer's other hilarious moments, we must first dissect what could be It's Always Sunny's most twisted episode yet, at least in some respects. Just when you think the Gang might honor Sam's memory with any amount of respect, we see Dee. So unless she's just in a coma of some kind, I gotta think Frank is marrying a corpse in Season 18. Elsewhere, the Season 18 trailer is filled with goodies, including the Gang getting all decked out to go to a Renaissance Faire, the Gang threatening a beer vendor's life for trying to sell them non-alcoholic suds, and the Gang playing some baseball.