When a Marine who just completed his third tour in Afghanistan, and who is known for his love of practical jokes, turns up dead on Halloween night, the NCIS team is called in to investigate.

Lance Corporal James Korby is found dead in his car. There's a hose running the exhaust back in through the window, making it look like a suicide.

It takes Ducky about five seconds to rule that out, though.

Korby was clearly murdered as his organs are frozen with liquid nitrogen and his entire frame brittle and freezing to the touch. This is more than a prank gone awry.

Someone got Korby to drink the nitrogen and staged his death to look like a suicide. The only question is who, and how the heck could they pull that off.

Tony can’t shake the hunch that the Sara, Korby’s wife and who has now been married to three Marines who have died, is somehow involved in the foul play.

Meanwhile, Gibbs and Ziva investigate leads that suggest Korby, known for being a prankster, even in the line of duty, wasn’t well liked among his fellow Marines.

His autopsy shows that he was recently poisoned - with paint thinner - and beaten up in Afghanistan. The beating was designed not to hurt him too badly, though, as the assailants didn't go near any vital organs.

Korby's squad leader is cornered about this by Gibbs and admits he approved a code red because he wanted Korby to shape up. People had problems with Korby and he wanted to teach him a lesson.

Furthermore, the squad leader himself poisoned Korby with a drop of paint thinner, hoping to get him shipped off on medical leave "for his own good." But he denies any knowledge of what happened to him back in the states.

Gibbs also deduces that Private Singer, who belonged to Korby’s unit, was having an affair with Korby’s wife, Sara.

Sara confesses that she was about to seal the deal with Singer, and that she was coming home to confront Korby around the time of the crime.

As Tony notes, she admits to being at the crime scene around the time of the crime. Yes, she says, but she still has no idea how he died.

Just as Tony is about to cuff Sara, Gibbs realizes Sara had nothing to do with Korby’s death, there was someone else with a real motive.

Rachel, Korby and Sara’s teenage stepdaughter, was about to cash in on a hefty trust fund and inheritance if she were able to off Korby and frame Sara.

­Nice try, Rachel. Do not try to fool Gibbs.