Blair and Serena went out drinking and S got hammered, stumbling into the street and almost getting hit by a cab. Dan happened to be in the area and ran out to save her. Later, lovestruck Dan reports that he lost the pie to a cab because of a drunk blonde. Alison remarks that Rufus used to have a thing for crazy blonde girls.
Also last year, Blair's dad was still around. Thanksgiving was a ritual for him and Blair, but her dad seemed to have had more of an interest in the male model Eleanor invited to dinner. Serena and Nate were guests at the Waldorf dinner, but Serena was drunk and reeked so Nate took her upstairs to clean her up. They got into a water fight in the bathroom, and doused Blair with water as well when she heard the commotion and came up.
Nate's dad was distracted through the whole meal by working on some Dutch business deal, with his wife telling him to cancel the deal, she'd write him a check herself. Lily came over after dinner to collect Serena, long passed out by then, and after they left, Blair and her folks sat down for some quality family bonding time.
That was last year. This is 2007.
Blair is excited to have her father back home for the holiday, but Serena ruins her good mood by confronting her about Chuck. Blair admits that she slept with Chuck twice. Serena and Blair exchange barbs about having sex and betraying best friends and being sluts. You know, usual stuff.
The van der Woodsens were supposed to have Thanksgiving at the Waldorfs, but Blair promptly nixes Serena and family. Dan hears about it and tells them to come over to Brooklyn for the Humphrey family feast so that they won't starve on Thanksgiving. Alison is there, too, however, which Lily is not aware of. As she arrives, Lily apologizes, saying she didn't know that Alison was back, and asks her to keep quiet about her past.
Blair is livid when Eleanor tells her that her father is staying in Paris this year. Eleanor called and uninvited him with the excuse that Blair didn't want to see him. Blair storms out, takes one of the desserts, goes in the kitchen and eats the entire thing, then throws it all up. Distraught and shaking, B phones S for help.
Nate (Chace Crawford) and his parents sit down to Thanksgiving. Things are not going well for Nate's mother. She lost her seat on a committee and the Archibalds were uninvited from the Waldorf's dinner, which means that her place in Upper East Side society is going down faster than the sobriety of Chuck Bass (not featured on this episode at all) on a typical night out.
Fed up, Nate leaves the table. He sits alone on a park bench, wondering if he should call Blair or Serena, but ends up calling neither. Instead, he goes home and finds his dad passed out, having taken MANY painkillers.
Serena immediately leaves the Humphreys' to tend to Blair. In an attempt to make small talk, Lily says she grew up in a ranch and used to have a horse named Rosewood, and the kids note that Rufus wrote a song called Rosewood ... dedicated to Alison. Alison realizes the song was about Lily and leaves the table, with everyone learning then that Lily and Rufus are old flames.
Dan (Penn Badgley) and Alison take a walk where she admits Lily was Rufus' first love. Lily likes to rub it in her face every chance she gets, too. Back at the loft, Lily lambasts Rufus out for this way of letting her know Alison is back in his life. Alison returns to overhear Lily talk to him about their kiss at Eleanor's party. Alison tells Rufus fairly simply to cut Lily out of his life, or don't expect Alison to stick around.
Serena (Blake Lively) brings a sad Blair back to the loft, where they find Dan, Jenny and Eric wondering if they are half-siblings. Overwhelmed by all they just learned, they decide to peace out through the fire escape.
Nate and his mother are at the hospital with mom in serious denial about. She thinks all she's ever done was make Nate's dad's life easy. Nate tells her to wake up! Later, Nate visits his father and says he knows his drug overdose wasn't an accident, and pleads with him to get it together, to hang on to his will to live.
The kids go out to a diner, where Lily (Kelly Rutherford) tracks them down. She sits down and orders fries. That's when the van der Woodsen's have the first real chance they've had all day to bond.
The Humphreys find themselves together again for some good old-fashioned football in a park near their neighborhood. Rufus (Matthew Settle) tells Dan not to expect Lily over for dinner anytime soon. He's focused on the future, not the past.
Blair (Leighton Meester) finally goes home, and Eleanor has a rare moment of honesty and emotion. She says that Blair's father has served her with divorce papers, but Eleanor can't find it in herself to sign them, and certainly couldn't face him during the holidays. It's very sad.
(Source: TV Fanatic)