Christmas signals the one-year anniversary of Nathaniel's death, and gets everyone thinking about their last moments with him. Brenda's book research nearly turns her fantasy world into a reality. Nate and Brenda are shocked by Margaret Chenowith's very special guest for Christmas Eve. Ruth's Christmas dinner brings David closer to Keith; meanwhile, Nikolai is stuck on Ruth's couch for a long convalescence with two broken legs. Claire's taste for bad boys drives her away from a well-meaning new boyfriend, and into an online relationship with a dangerous man from her past. Federico stirs up conflict in his family when he reveals the truth about Ramon. Nate receives a gift from a biker's widow that just might help him live his own life to the fullest.