Caleb is on the verge of facing serious jail time, but Sandy tells him to confess his involvement with Renee, which could destroy both their relationships with Kirsten and the rest of the family. Jimmy and Julie's feeling for each other deepen.
Caleb's trial is approaching, and Caleb is starting to realize that he might be going to prison. Sandy urges him to come clean with the truth about Renee and Lindsay. He says it will be easier to face Kirsten and Julie, than it would be to go to prison. Caleb isn't so sure, and is reluctant to come clean about his affair with Renee. With that, Sandy walks away from the situation, saying he is finished. Back home, Seth is ecstatic about his favourite holiday, Chrismukkah. After hearing that the Cooper-Nichols will be attending their
annual dinner, Seth is concerned that the Gentile to Jew ratio is too high, so he is on a mission to find Jews to invite to dinner. On the topic of invitees, Seth reveals that Alex is away for the holidays. Ryan wants to invite Lindsay but is hesitant about rushing things. When Lindsay mentions she has never had a good Christmas, Ryan invites her over. On Jimmy's boat at the harbor, Julie and Jimmy are in bed together. Julie feels that they might be rushing things, and she doesn't want to commit adultery. But she rationalizes their romance as Caleb might be going to jail, so
they have sex. Up the shore, Sandy meets Renee to discuss the case against her and Caleb. He urges her to come clean about the affair she had with Caleb, or she could end up in prison for accepting bribes from Caleb (which were actually support payments for Lindsay). She is just as hesitant as Caleb, afraid to tell Lindsay the truth.
Back at school, Marissa and Summer talk bout how sucky this Christmas will be. Zach and D.J. are both away with their families, and so they are both faced with spending the holidays with their respective dysfunctional families. When Seth sees how miserable they both are, he invites them by his house for Christmukkah. That
night before dinner, Seth tells Ryan that Summer and Marissa are coming for Chrismukkah. Ryan isn't happy about that though because he doesn't want Marissa and Lindsay hanging out together. When they go outside where Sandy is barbecuing, they mention that they invited the girls over, to which Sandy tells them he doesn't think that is a good idea. He says that since Lindsay is involved in Caleb's case, the timing probably isn't the best for her to come over. Ryan agrees but wonders how Lindsay could possibly be involved. Seth and he joke about how Lindsay is a drug dealer or an illegitimate love child of Caleb's. Sandy glares at them, revealing that Caleb is indeed
Lindsay's father. He tells them not to tell anyone. The next morning, Ryan plans to uninvite Lindsay for Chrismukkah, but he asks Seth to uninvite Summer as well, so it doesn't look like Lindsay was the only one. Seth reluctantly agrees, and they both head of to break the news to the girls. When Ryan gets to Lindsay's house though, he sees how excited she is about Chrismukkah and can't break her heart. The same happens with Seth and Summer. She takes him Christmas tree shopping and professes that she believes they are finally becoming just friends. Of course Seth can't uninvite her now. Seth and Ryan both return home and confess that they both
chickened out. As everyone is arriving at the Cohen house, Jimmy and Julie sneak off to the kitchen to kiss. Kirsten walks in and sees them close together, but doesn't say anything. When Renee and Lindsay arrive, Lindsay is surprised to find Ryan with Seth, Summer, and Marissa. Renee wasn't going to come in, but a few minutes later rings the doorbell and asks Kirsten if she can talk to her. At the same moment, Sandy is in the den with Caleb telling him to confess everything. As Caleb comes in to the kitchen to tell Kirsten the truth, he finds that Renee is already there. Everyone else enter the kitchen at the same moment, including Seth, Summer, Marissa, Ryan, Lindsay, Julie
and Jimmy. Everyone wants to know what Caleb has to say, and although he is reluctant once more, he admits that sixteen years ago, he had an affair with Renee, that resulted in a child - Lindsay. With the news, Lindsay storms out of the house, and Renee follows. Caleb tries to apologize to Kirsten, but she slaps him, and asks him to leave. Julie then slaps him, telling him he should be ashamed. Marissa, Ryan, Seth, and Summer are left standing in silence. Upstairs, Kirsten is fuming with Sandy for not telling her what he knew. When Caleb comes up to explain, Kirsten throws a vase at him. Seth has followed them all upstairs and advises his grandfather that he should
leave. Kirsten barricades herself in the master bathroom. Across town, Ryan has gone to see Lindsay at her house. When he asks how she is doing, she tells him that she thinks it would be best if they didn't see one another anymore, or at all for that matter. She doesn't want anything to do with the Cohens, and she closes the door on him. Back at the Cohen house, Summer and Marissa wait for Seth in his room. When Seth joins them, he says that he thinks Chrismukkah should be cancelled. Later, Summer announces that she has a plan not to let Chrismukkah die. At the Nichol's, Caleb promises Julie that he has no more secrets, and that he will be free now, and they can get on with their lives. Julie can't believe that he cheated on his wife. Caleb says that he wants it all to be over, and that he needs Julie to forgive him. Julie isn't sure she can do that. She leaves to find Marissa. Later in the evening, Ryan meets Sandy in the kitchen. Kirsten still hasn't come out of the bathroom and Sandy has given up trying to make her. Ryan wants to give it a try. When he goes up, she won't answer the door for him either, but he asks if they can talk about Lindsay. When Kirsten asks how Lindsay is doing, Ryan says that it depend on whether she figures out the Cohen family is good at taking in new members. With that, Kirsten comes out of the bathroom. She says that she isn't sure she is ready to accept Lindsay is her sister, but that she does know that Lindsay seems like a great person. On the water, Marissa and Summer meet Jimmy at his boat. They need a generator for their plan. Before they leave to get the generator, Jimmy asks Marissa if she's talked to her mother lately. She shrugs it off, and leaves with Summer. When they leave, Julie emerges from inside the boat. They have been together again. When Jimmy asks if they are making a mistake, Julie tells him that she wants to be with him. On the beach, Seth finds Lindsay sitting alone. He tells her that he understands how overwhelming things might seem, but that she is a Cohen now, and he gives her a stocking. They walk back to her house to find that Kirsten, Ryan, Summer, Marissa, and Sandy are all there waiting. They have decorated her house with lights and Christmas ornaments, and they have put up a tree for her and Renee. Lindsay is overwhelmed, and Kirsten welcomes her to the family. They all celebrate with Egg Nog and Latkes, and a Chrismukkah hymn by Seth.