When an injured petty officer stumbles into a crowd of high school students at bonfire party and dies, NCIS' investigation turns up more than anyone suspected.
The NCIS team finds the petty officer's wrecked car nearby, riddled with bullet holes. Ducky discovers that the victim died of injuries sustained in the crash, but also shows evidence of a severe beating -- and of having thrown a few punches himself.
Evidence leads to a house where the team finds evidence of a fight, and a passle of nosy neighbors who witnessed a brawl -- or a fight club, as the team later finds. DNA evidence leads to the victim's best friend, Sam, who has also been beaten pretty thoroughly.
Abby and McGee recreate the car crash using paint chips and skid marks.

The paint chip analysis leads to an heiress and her husband/lawyer, Dale Kapp. Abby matches Kapp's fingerprint to one found on the victim's car.
When Kapp disappears, the manhunt is on. Abby and McGee ferret out an IM chat transcript that leads to a co-ed's apartment that turns out to be a honey trap. And that's when it gets complicated and Kapp turns up dead....
The writers did a good job of making what could have been a very simplistic fight club story and making it very complex -- and keeping  the light bits light. All of the cast members show depth and range in this episode -- and Tony, McGee, and Ziva's participation in an online competition site is priceless.
Tony's movie references in this episode include Fight Club, Saturday Night Fever, Psycho, Wizard of Oz, The Matrix, and Desperate Housewives. Did I miss any? Let me know in the comments!