-Gloria rents a cabin to celebrate her first Christmas as a U.S. citizen

-Cam and Mitchell practice caroling to redeem themselves for last year

-Phil talks about how much he loves his sheepskin coat

-They arrive at the cabin only to find it's hotter than at home

-Phil refuses to take off the coat

-Haley and Andy try to keep their relationship hidden from the family

-Turns out there's a strange woman already in the cabin, Cam invites her to stay

-Lily finds a locked room in the cabin, and Manny and Luke try to scare her

-Phil gives Andy his old realtor blazer and they share an emotional hug

-The mystery woman is a professor at MIT, and bonds with Alex

-Jay announces his retirement, and his choice of successor (who is not Claire)

-Claire storms off into the woods followed by Phil

-Turns out Jay made up his successor to make sure Claire really wants the job

-Cam and Mitchell try to incorporate Lily into their caroling but she's terrible

-Manny and Luke continue their attempts to scare Lily

-Alex realizes she needs to change

-Alex tries to help Haley and Gloria, but they think she's being sarcastic

-Claire confronts Jay and they get into a fight

-Lily screams after hearing sounds from the mystery room

-The whole family comes running and discovers Haley and Andy

-Andy tells the truth about the affair with Haley and Andy

-Gloria brings Beth as a surprise

-Phil gives Andy a stern talking to

-Cam and Mitchell are upstaged by Alex and the MIT professor's rendition of Silent Night

-Beth reveals that she's seeing two other people

-Andy is upset that Beth cheated on him (Haley is not impressed)

-The whole party devolves into bickering

-Gloria yells at everyone to stop arguing

-Jay gives Claire CEO business cards

-The family shares a brief perfect moment

-It starts snowing, but it's actually ash from a forest fire

-Luke gets left behind locked in the mystery room