A double date descends into chaos when Mac and Desi witness a murder in the back of the restaurant, and as they work to find the killer, Riley tries to keep the secret about her and her friends' "day jobs" from her new boyfriend, Aubrey.

While Mac's friends surround him during his time of grief, Los Angeles' power grid is taken hostage in a ransomware attack resulting in a citywide blackout, and the team discovers the code used was written by Riley years ago.