Michael suspects Donna is cheating on him and puts P.I. Dwight Schrute on the case. Meanwhile, Andy is frustrated when no one takes his customer's complaint seriously.

Michael could not be happier when Toby has to take a leave of absence and corporate sends Holly Flax to cover for him. Pam is forced to do a second Christmas party after Michael wants the party to be on the day Holly returns to Scranton. Meanwhile, Jim regrets agreeing to a snowball fight with Dwight.

Andy makes a game-changing decision and takes a road-trip odyssey in the name of romance. Elsewhere, Nellie arrives at the Scranton branch and sets out to seize the manager position.