After Vic disowns him, Shane turns to the Armenian mob for help. Vic gets more involved with the San Marcos investigation, while Dutch and Billings are able to track down someone who survived the massacre.
House treats a 16-year-old chess prodigy who gets everyone on the team annoyed with his behavior. Foreman is upset with House because he thinks his boss sabotaged his job interview with another hospital.
Alan defends Brad and Denise's priest after he's arrested on their wedding day on charges of sheltering undocumented immigrants; Jerry helps a woman with a pet duck who was evicted from her apartment; and Denny counts a coveted sports trophy among his possessions.
The team investigates the death of a partially clothed teenage boy wearing a leather mask. The detectives discover that the victim's best friend is the killer and has a video, showing that the boy's death was the result of a backyard wrestling match gone wrong.
There's a serial killer on the loose marking all of his victims with a Y on their chests and one or more of the csi's lives are in danger in this season 5 finale
Goren and Eames find a scrapbook belonging to a serial killer on death row. It suggests that he may have had more victims than previously known.
Russia presses the White House, while Jack must try to thwart the Chinese and his oldest antagonist simultaneously.
It's still Marshall and Lily's big wedding day but now we're at the reception. Robin tries to tell a story but keeps getting interrupted. Barney tries his hardest to figure out Ted and Robin's secret.
Poised to become a member of Congress and maybe more, Nathan considers the cost to those he loves, along with his mother's advice and Linderman's prophecy. As he prepares to face Sylar to the death, Hiro learns of his lineage from his father. While various "heroes" fatefully arrive in New York City, Peter and Claire attempt to leave the city before the foretold explosion. H.R.G.
Evelyn's boyfriend, Teddy, invites Alan and Charlie to go with him to Las Vegas on his private jet. The boys confront their individual 'daddy issues'
Doug and Carrie's marital tension continues, as they ponder whether they have a future together. Arthur and Ava's wedding day turns problematic.
At Arthur's wedding reception, Doug and Carrie's marital tension continues, and they ponder whether they have a future together.
Tommy and Jimmy have two different ideas on how to save the Donnellys. Tommy hatches a plan to get the family, along with Jenny and Joanie, out of town.
Alex's double life is finally bringing in the cash she wants but hiding everything from everyone is taking a toll on her schoolwork and her connection with Paige. But making money is the only way she and her mother won't get evicted - Alex tries to convince herself she's making the right decision. When Sean and Emma are not talking, she will have to go through her scariest experience yet all by herself. Marco also learns that sometimes love is very, very messy.
When Brian's dog finds a body, it prompts two people to confess to murder. It turns out that the body is over 600 years old, so Sandra, Jack, Brian and Gerry must discover why the pair took responsibility for a crime they couldn't possibly have committed and if they are the perpetrators of other killings. Elsewhere, Strickland is rather keen for them to solve an even more tricky mystery that is closer to home.
Kevin acts as McCallister's attorney when a radio host makes accusations against his war heroism. Also, Tommy and Julia must face a tough decision regarding their newborn babies.
A girl's parents retain Peter to sue Cambridge University because she has not been offered a place. Peter visits his old tutor to investigate and learns that Simon contacted him for money shortly before he disappeared. Gloria is upset because it is a year since her husband died, and her son is picked up by the police for breaking windows in the town. Lyle assists Snell in a scheme to stop the gas company building on a piece of local grazing land. Beatrice uses Lyle to win back Alan, but on discovering that Alan has again been cheating on his sister Peter confronts him.