It’s April, and yet Christmas music is blaring at Frank and Donna’s house. The family is all gathered at the dining room, and they’re all tied to their chairs. Donna appears to have been strangled, while Frank and their children Lance and Jenna have been shot.

While the BAU investigate the crime scene, they find another man in the house and he’s covered in blood. His name is Ezra, and he’s Lance’s boyfriend. Ezra said that the celebration was for Donna’s birthday. He said that Frank always hated it that his son was gay, so when he and Lance started fighting, Ezra said that he went up as he had too much to drink and passed out. Rossi doesn’t think that Ezra could have done it because the crime scene was too elaborate to be set up by someone who was too drunk.

The team investigates the other son, Dillon, who wasn’t at the house when the murders occurred. He has a nice apartment and a car, but no means of livelihood. His father was sending him money for seven years, but that stopped 10 months ago.

Dillon says that his father may have killed everyone. He also told the team that Ezra has a temper and that he once kicked Frank’s car.

Meanwhile, Jenna’s boyfriend Marc says that he was working at the time of the murders. He says that Frank was paranoid and had a habit of accusing people of things, like telling him not to get Jenna pregnant. Marc says that he and Jenna aren’t sleeping together because they want to wait until they get married.

Later, the team finds out that Frank has been paying a consulting fee of $20,000 to a fake company and that the payments also stopped 10 months ago. The payments were made twice a year — on May 3 and Dec. 24, so the Christmas music must be significant in this case.

Dillon reveals that his father had an affair during his freshman year of college and when Dillon found out about it, his father started paying him to keep quiet. The woman’s name is Cora Gilliam, and Dillon said that she and her father have been together for 26 years. Dillon also said that at the time they started having an affair, Cora had a 2-year-old son.

Reid does the calculations, and he says that the child’s birthday falls on May 3 and that the kid is more likely Frank’s. Moreover, that child turns out to be Marc — Jenna’s boyfriend. He was the one who suggested that they shouldn’t sleep together because he knew that they were half-siblings.

Apparently, Cora has been lying to Marc all this time and she’s been telling him that his father has been lost in action while serving overseas. Marc is waiting for Cora at home, and pulls out a gun on her and tells her that he has a surprise for her. He reveals Frank, dead and tied up at the head of the table, and tells Cora that his father is finally home at last.

At this point, Hotch and Morgan enter the house and arrests Marc.

“Criminal Minds” airs on Wednesdays at 9/8c on CBS.