The film starts at a Chicago airport. A group of Marines have just returned to the US from Iraq. As the Marines leave, one Marine remains and makes his way towards the exit. The soldiers name is Jesse Rodriguez (Freddy Rodriguez). The film cuts to a house where a man, Edy Rodriguez (Alfred Molina) is on a ladder nailing up a welcome home sign for Jesse. The woman, his wife, Anna Rodriguez (Elizabeth Pena) gives him a rather disgruntled look before leaving to prepare for Jesse's return.
Edy then travels to his store, a small neighbourhood supermarket. Along the way, and even in the store, Edy appears to be quite popular with the ladies.
Back at the airport, Jesse finally meets up with his friends Johnny (Luis Gusman) and Ozzy (Jay Hernandez), who have come to pick him up. On the way to his fathers store, Jesse takes off his eye-patch to reveal that he can still see, but the area around his eye is badly injured. After some prompting from Johnny and Ozzy, he reveals that he was the lucky one, as his friend Timmy (I think that was his name, he never shows up in the film) was not as lucky and Jesse feels some guilt for this. On the way, the three pass a park and Jesse tells them to stop. The park was their childhood playground and the three take a little time off to play a game of softball and reminisce. While at the park, Ozzy spots Hector (Alexander Bautista), the man who killed his brother, recently been released from prison. Ozzy stares at Hector, and Hector stares back, however, before Ozzy is able to make his way to Hector, both Jesse and Johnny hold him back the they make their way to Edy's store.
Upon arrival at Edy's store, Jesse gets a warm welcome from the staff and neighbours being something of a war hero to those around him. Edy, Jesse, Johnny and Ozzy head back home to celebrate Christmas. Jesse is given a warm welcome from his mother as others begin arriving.
Jesse's sister Roxanna (Vanessa Ferlito) arrives by taxi, although everyone assumes she came in a limo because they all assume that she made it big in Hollywood as an actress. Jesse's Brother Mauricio (John Leguizamo) also arrives, along with his wife Sarah (Debra Messing). Sarah greets Anna and it is evident that she is not exactly comfortable around her in-laws but she is making an effort, even speaking a bit of Spanish. However, the topic drifts towards children and Anna makes it very clear that she wants grandchildren, but Sarah is a very business driven woman and isn't ready for kids, this causes some tension between Sarah, Anna, and Mauricio. After things settle down, everyone sits down and begins to catch up and each person's story is brought up: Jesse has just returned from a three-year tour in Iraq and is being prepared by Edy to take up the family business; Roxanna is waiting on news regarding a new TV deal; and Mauricio and Sarah are both in finances and making a great deal of money, but don't have time for much else. The conversation moves towards Jesse's experience in Iraq, but it's obvious that he does not want to talk about it (this is important later). Soon after, Marissa (Melonie Diaz), her son, and her boyfriend Fernando (Ramses Jimenez) arrive. Marissa is Roxanna's best friend from childhood, and Jesse's ex-girlfriend. It is evident that Jesse still has feelings for Marissa and vice versa, but there is much tension in the air.
After everyone has arrived, they all sit down for Christmas dinner. Everyone is digging into an abundant pile of food, chatting away, while Sarah sits there with a look of awe on her face as she has never experienced the holidays with Mauricio's family. Edy is about to give a toast to everyone but gets a call. It seems that Edy has been getting a lot of calls, and often runs out when he does which gets Anna suspicious that he is having an affair, and cheating on her again (there was one previous incident in the past). Well, when the phone rings during Edy's toast, he stops to answer the call, and having broken the last straw, Anna proclaims that she is divorcing Edy. At first everyone thinks this is a joke, but it is soon evident that Anna is dead serious. Edy reacts with little emotion, saying that if it is what Anna wants then he can't really do anything about it. Mauricio is vehemently against this and tries to get some support from Jesse, whose response is similar to his father's, this angers Mauricio further. At this time, Johhny, Ozzy, Marissa and Fernando excuse themselves as it is a family matter. After more arguing, everyone leaves to vent, except for Sarah, who stays at her seat and continues eating, sort of a gesture of comfort/support to Anna; and the two have a somewhat awkward yet endearing bonding moment.
At night, Jesse is about to go to bed when Edy shows up, having been kicked out of the bedroom and is not bunking with Jesse. Father and son have a conversation about Jesse's experiences but Edy can't really get much out of his son.
Later that night, Mauricio is up in the Attic thinking about the night's events when Roxanna shows up. The two share a drink and Jesse shows up. The siblings reminisce about their childhood and what the future will be like after their parents divorce. Both Roxanna and Jesse are relatively neutral to the matter, but Mauricio is very against them. Being the only one of the three to be married, he believes that after 35 years of marriage, their parents have to have at least some love for each other, and that there is always a chance to salvage what remains of their marriage and he says all this while in his underwear (humorous scene).
In the morning, Jesse catches up with Marissa while she is walking to work. She still hasn't forgiven him for leaving her several years ago. As it turns out, Jesse didn't want to stay in town and follow in his father's footsteps and ended up enlisting in the marines. While in Iraq, his unit was holed up in a building for the night, Timmy offered to take Jesse's watch so he could grab something to eat. While Jesse was getting some food, a rocket propelled grenade was shot into the building and Timmy was killed, while everyone else was injured. Ever since then, Jesse blames himself for Timmy's death since it was supposed to be his watch, and his life that would be lost. Marissa sympathizes and forgives him.
Back at the house, Mauricio is attempting to get Anna and Edy back together by bringing over their priest, Father Torres (Manny Sosa). Anna returns home and Mauricio brings her into the kitchen. Anna is clearly drunk and is very upset. Another argument ensues and everyone is at everyone else's throat. Mauricio argues with Anna regarding having children, Roxanna reveals that she's not a star and can barely make ends meet. Both Mauricio and Roxanna think Jesse has it easy, since he got the store to manage as soon as he returned. However, Jesse doesn't want to manage the store and his guilt over Timmy's death has been haunting him since his return. After more arguing, everyone leaves. Roxanna, Jesse and Mauricio end up in a bar to drink/party to vent off some tension.
Sarah gets back to the house and finds that everyone has left. Edy offers to give her a ride to the bar where everyone is. While driving Sarah to the bar to meet the others, Edy appears to have a heart attack and stomps on the brakes. Luckily, they skid into a parking area and no one is injured; Sarah is able to fetch Edy's medication from the glove box in time. As Sarah looks at the bottles, she realizes that Edy is really very ill and that that's the reason he's getting those phone calls (the doctor). Edy makes her promise to not tell anyone, since he doesn't want anyone to worry so they can enjoy the holidays.
At the bar, everyone takes the chance to have some fun, drinking and dancing. Sarah gets hammered and starts dancing with Mauricio, who can't dance at all but does so anyway. Everyone is having a blast and Jesse takes the time to talk to Marissa. Roxanna, receives a call from her agent (with no actual news regarding the new part), goes outside to answer the phone and have a smoke. While Roxanna is out having a smoke, Ozzy comes out to talk to her. It is obvious that Ozzy likes Roxanna, but she is a bit apprehensive as she sees him as a gang-member type person, although Marissa has noted that he hasn't been part of that crowd for quite some time.
Roxanna and Ozzy go to the local ice rink to talk, and Roxanna tells him that she really isn't much of a star since she has only had a few small roles in TV and commercials and can't really get a big part. Ozzy assures her that she will get her big break, but she is not so sure. Roxanna mentions returning home since her career isn't going anywhere, and her mom may need her around during the divorce. Ozzy is happy that Roxanna may stay, but is supportive of her career.
The next day, everyone prepares to have a little Christmas carol parade, where people travel from house to house carolling, and people join along the way until nearly the entire neighbourhood has joined in. The parade ends with everyone arriving at the church for a big party/dinner. Everyone is dancing and having fun. Fernando goes off to get something to drink and Jesse asks Marissa for a dance. The two begins to get close and Jesse leans in to kiss her, just as Fernando lunges in and hits Jesse. Jesse (being a marine) pummels Fernando before his friends drag him off. While this is happening, Ozzy can't take it any more and leaves to confront Hector. Hector is returning home with his mother and sees Ozzy. Knowing what Ozzy has come to do, he tells his mother to go into the house and make dinner, while he goes outside with Ozzy. Outside, Hector tells Ozzy that he's ready to die, and has been for many years while in prison. Ozzy is visibly struggling to decide whether or not to kill Hector, just then, his phone rings, it's Roxanna. Ozzy gives up, and let's Hector live, and leaves to meet Roxanna. Ozzy and Roxanna go to the river, where he gets rid of the gun, and the two kiss.
After midnight mass, Edy drives Anna home. On the ride home Anna confronts Edy about his affair, but all Edy will say is that all he wants is to have a good Christmas with the whole family, and that they should keep it together until the kids leave. Anna says that after the kids leave, there will be nothing more to talk about.
Edy is now alone in the kitchen, drinking. Jesse and Mauricio return home and join their father, each drinking to their own little problems. Edy, decides to do one last thing for Anna and finally cut down that tree so the three go outside and secure the tree to a chain that is connected to the rear bumper of Edy's car. Edy guns the engine but the rear bumper comes off and he crashes into a parked car, injuring himself.
Anna calls the ambulance and Edy is rushed off to the hospital. Before the ambulance leaves, Sarah runs out to Anna and hands her all of Edy's medication since she's the only one who knows how serious his health is. The whole family is at the hospital to check on Edy. It turns out that Edy has cancer, it's serious but he's being treated for it. Anna finally realizes that Edy was not cheating on her, and that the Susan that Edy was talking to was actually his oncologist. The couple make their peace and profess love for each other, and then Anna smacks Edy for being stupid and not telling her sooner.
Having seen how frail life can be, Sarah decides to have children, and take the new position at work, and will try to balance both in her life with support from Mauricio.
Back at the house, Anna is teaching Roxanna and Sarah how to cook with moderate success. Roxanna gets a call from her agent, and when she returns, it appears as though she has not gotten the part. Outside the house, Ozzy comes by to talk to Roxanna and she reveals that she actually did get the part, but it wasn't a very big part anyway, and she thought it would be best to stick with her family during these times, so she turned down the part.
The next scene shows Jesse visiting Marissa to drop off some Christmas presents and to apologize for his behaviour the previous night. She forgives him, but she has a relationship with Fernando now and a happy family life. Jesse concedes and wishes her a happy life. After leaving, Jesse sits on a park bench, making a call to Timmy's parents to tell them about their son and how he died so he can get closure and move on.
The final scene shows Edy, after discharge from the hospital, taking Jesse to his store, who has now decided to take up the family business instead of going back to Iraq.