Booth and Bones were expecting nothing less than a horrible Christmas. Booth's son was heading to the mountains with his ex. Bones' dad is in prison. Even though she arranges for the "conjugal" trailer to be used by her brother, his wife, their kids, and her dad, she was going to Peru for an anthropological study. But even the trailer is a bust because they can have it but no decorations.
There's also a body and a killer and blah, blah, blah.
But the last scene got me. Booth's son doesn't go to the mountains and they get Christmas day together with "two trees." We don't know what that means. Cut to Bones who doesn't go to Peru and is in the trailer with the fam. Bones calls and tells her he and his son want to give her present to her. She says, "Later." And he says, "Look out the window."
There Booth and his son stand beside a Christmas tree with multicolored lights plugged into the car battery.
Some day some one is going to know me well enough to know that that simple act would have made it the best Christmas ever for someone like me.
Until then ... I cry. Sappy, I know.