Mia Sullivan (Monica Calhoun), wife of Lance Sullivan (Morris Chestnut), has sent letters requesting that the old gang joins them for Christmas: Harper Stewart (Taye Diggs) and his almost-ready pregnant wife Robyn (Sanaa Lathan), Julian “Murch” Murchison (Harold Perrineau) and wife Candace Sparks (Regina Hall), her best friend Jordan Armstrong (Nia Long) and boyfriend Brian McDonald (Eddie Cibrian), Quentin “Q” Spivey (Terrence Howard), and Shelby Taylor (Melissa De Sousa).
Shelby is living the dreamed life as a cast member of a popular The Real Housewives television show franchise, and is now a prominent reality television star. Q is now a successful brand manager and heavily connected to prominent celebrities.
Years after his debut novel, Harper is struggling with writer’s block and financial difficulties, having been recently relieved of his faculty position at New York University, this compounded to his wife having difficulty conceiving. Harper’s agent suggests that Harper writes a biography on his estranged best friend, Lance, who is set to retire from football. Though Harper and Lance are on good enough terms to maintain an acquaintanceship, Lance makes an appoint to keep an emotional distance. Harper reluctantly agrees to the biography, but keeps the idea a secret.
The Murch family now includes two little daughters and Julian finally opened and runs a renowned school, with his wife former stripper, Candace, as his head of admissions. His main donor, however, abruptly terminates his relationship with the school when he learns of Candace’s past. It is then that Julian finds a YouTube video of his wife stripping and accepting money for sex at a fraternity party. Julian confides in Quentin.
All the friends arrive at the house, the first time they’ve come together in 14 years. At dinner times in the movie the old friends catch up but old tensions resurface and grow.
Brian leaves for his family’s annual Christmas gathering in Vermont. As he leaves, Jordan tells him that, while she loves him, she does not need him. ‘Everybody needs somebody, Jordan,’ Brian says.
Among other things, on another night the band has a good after-dinner time with the men dance and lip-sync to “Can You Stand the Rain” which Mia notes works well to patching up old wounds between Lance and Harper.
It is when Harper goes down to the kitchen that he finds Mia throwing up blood. Mia reveals to Harper that she was diagnosed with cancer more than a year ago and it’s terminal but that she needs Harper’s help to guide Lance coming to terms with it.
At breakfast the next morning, Q and Shelby accidentally switch phones and Shelby finds the Candace video on Q’s phone. She tries to use it to coerce Julian to resume his previous relationship with her but Julian rebuffs her advances. Not long afterwards, Candace loses patience with Shelby and confronts her, which leads to a physical altercation after which Candace leaves the house with her and Julian’s daughters. Later Candace returns and reconcile with Julian through dialogue.
The ladies are preparing for a spa day when Mia collapses while trying to hang a Christmas ornament. The instance forces Harper to tell the rest of the friends about Mia’s illness; the friends are supportive.
While Harper is wrapping the children’s gifts, Lance approaches him and the two reminisce about their college days and seem to overcome their differences. The next day, the gang volunteer at a shelter, with Q as a grudging Santa Claus. But Lance soon stumbles across Harper’s iPad and journal in Mia’s purse, and a mock book cover for his unauthorized biography on the tablet. Lance angrily confronts Harper and tells him to stay away from him and his family, ‘forever this time’. Mia unsuccessfully tries to calm Lance down. He takes Mia home, leaving Q and Harper behind where Harper finally breaks down and admits the truth of his financial situation. After giving humble words of comfort to Harper, Q vows to take care of his debts as a friendly favor.
Lance is still heated over the biography when Mia challenges Lance to acknowledge the truth. She is to blame equally with Harper for the longtime feud between the two men by virtue of her having been in full knowledge of the pain her affair with Harper (see The Best Man) would incur on Lance. Mia then takes off her wig, forcing Lance to also acknowledge the severity of her condition.
Christmas Day is also Lance’s big game. Brian returns, affording Jordan an apology. Lance starts a troublesome first half. Mia calls Harper to speak to Lance, inspiring him to ultimately break the all-time rushing record in a game-winning performance. The men then rush home to Mia who not long after dies.
At the funeral service, Harper delivers a heartfelt eulogy confounded as to why God would take a human away to heaven on the same day he gave his Son to the earth. Lance later thanks his friend and in the conversation affirms, ‘But God is always there when we need him.’ Harper is encouraged: ‘That is why you will always be the better man, Lance.’
All are shown to reconcile and Q and Shelby come to terms with their romantic incompatibility. Shelby gives Julian a check for two million dollars, covering the funding gap created by the donor pull-out with no special favors in return. Later Brian, Jordan’s boyfriend, promises to assist by some investors he knows personally.
Robyn’s water suddenly breaks. Lance, Harper, and Candace try to rush her to the hospital but they get stuck in traffic; it is thus Lance who delivers Harper’s baby in the backseat of the SUV. The healthy baby girl is named Mia.
Ten months later, Harper and Lance are closer than ever and Harper has now written Lance’s biography. When Lance visits Harper and Robyn at their house in New York City, Harper gets a phone call from Q wherein Q announces his anticipated marriage but immediately warns Harper that he better not have had slept with his bride.