Doug starts by showing a flashback of last Christmas when Pam and Russ were happily married, then it zooms to now, with Pam crying at the Barber's house, because she misses Russ. When Russ shows up at the kids Christmas pageant, he has to stand in the divorced fathers section. Afterwards, he talks to Doug. When he CLAIMS to miss Pam, Doug tells him that she has been missing him too. So Pam and Russ start dating again. But when the Barbers are picking out their family Christmas tree, Janine finds out about Doug talking to Russ, which instantly makes her mad. She says that if Pam is hurt by him again, it would be Doug's fault. When Doug goes to talk to Russ, he sees him kissing his old girlfriend. So at the Barber's Christmas party, Doug confronts Russ and tells him to tell Pam. But Doug leaves him alone long enough for him to leave without telling her, so Doug is left to do it. Pam is really mad, but in the end, Janine convinces Doug that he helped, and in a way, saved Christmas. (thetvdb.com)