In the premiere episode, Doug's kingdom comes under attack when his recently widowed father-in-law, Arthur (Stiller), moves in rather than go to a retirement home, turning Doug's TV room into Arthur's bedroom.

While poring over an old photo book, Arthur shows Doug a picture of Carrie's mother, and Doug is stunned at how overweight she became as she aged.

Doug fears that Carrie's new job is taking her away from him.

When Doug finds out that Richie's wife is cheating on him, he is torn about whether or not to tell Richie the truth.

When Doug's favorite aunt comes to visit, Arthur falls in love with her.

Carrie feels bad that Arthur has no friends and encourages Doug to take him out and do things with him. Doug reluctantly lets Arthur tag along and discovers that Carrie is grateful for Doug's generosity. Really grateful.