A judge ends up a real-life casualty when he takes part in a reenactment of a famous historic duel. Goren and Eames question the victim's opponent, whose wife is running for mayor of New York City.
Debbie's glad to have her dad back at home, but Monica's not happy with all the attention Frank is giving her and tells her it's time she found herself a boyfriend. Also Ian catches the eye of someone he least expected.
To assist Willa in her investigation of a teenage girl's murder in a small California town, Lucy delegates her onetime mentor to help. In the meantime, Holt and Lucy's growing attraction towards each other comes to a boil. Meanwhile Julia slumps into the arms of Garbo and deeper into drugs.
After catching an international arms dealer, the NCIS team learns that Navy's highly classified weapons system will be sold to "La Grenouille," an important arms dealer. To stop the transaction, the team will send Ducky undercover. Meanwhile, another government agency appears to be working on the same case, with different plans.
Life in the Sutton neighborhood isn't getting easier when one of their neighbors takes an entire bank hostage, and Eddie has to break a promise to Jenn.
The four Nitti boys are at war with each other and their Mom. Darren (10), Matthew (8), Devin (6) and Jared (5) are so violent that they leave serious welts and scars -- the oldest son has hit, kicked, punched, spit and head-butted his mother, Lisa. Darren admits that he likes hitting because it "takes out his anger." Lisa and her boyfriend, John, have been together for two years, but Lisa doesn't know how to manage her children without resorting to anger or threats to call John, who has a lion's roar that intimidates the boys. The violence between the children heats up in the car, and Lisa and John often can't get more than two blocks from home without having to pull over to manage the chaos. Dinnertime can go into an hour of overtime, as Matthew refuses to eat, and when the younger kids refuse to go to bed, there's no rest for these weary parents.
Heidi and Audrina go out to have dinner and they finally talk about their issues and Spencer.
Charlie sets Alan up with their new neighbour. But he gets jealous when the two form a bond.
When Davis buys a classic table hockey game and sets it up at the DRPD, he finds that he's set events in motion that lead to the ultimate showdown... the Summit Series between Karen and Brent. The whole town takes sides in the tournament, and Hank decides that he now wants Karen as his role-model, after watching both her and Brent train. Lacey joins a new club and nominates Emma for some long-overdue recognition.
A mother returns home from work to find her baby girl dead in her cot, and her nanny has Vanished. D.C.I. Connor and the team take on this emotive case involving this ultimate abuse of trust. With the nanny on the run, it seems an obvious conclusion. But the more they investigate the case, the more complicated it becomes and they find themselves wondering who is the real victim and who can they really trust?.
Harry loses his cool with 3 swimmers that he's forced to rescue just seconds after warning them not to swim in a dangerous area. However, calling them "imbeciles" and "idiots" puts him in hot water.
Daniel Negreanu returns to the table after a short stint in the commentating as Doyle Brunson, Jamie Gold, Bill Chen, Victor Ramdin, Daniel Alaei, and Mike Matusow join "Kid Poker" for another High Stakes Poker cash game.
Kris, Matt and Junior try to change Ken's mind when he decides to sell Wildfire's son Flame; Dani moves into R.J.'s trailer.
Family troubles: Jack with his brother and father while Morris worries about his own brother.
Hiro deals with explaining his new heroic path in life to his ambitious sister and tycoon father. Niki has the chance to reunite with D.L and Micah. Claude's mentoring of Peter leads Peter to question those closest to him. Claire goes to a trailer park looking for her birth mother. Sylar wears a disguise and makes a move against HRG.
C-Note gets into a tricky situation when a robber holds up the diner he is in and demands everyone go into the storage room until the police arrive. Michael, Lincoln and Kellerman get closer to revealing the conspiracy with the help of Sara. Mahone finds a new ally in Bellick.
When a funeral conflicts with the Super Bowl, the gang vows to avoid hearing the score and watch it together on Monday. This proves difficult, as Marshall is threatened with the score by a boy in Lily's class, while doing the news puts Robin in danger of finding out who won.
When school is closed for a snow day, Chris is the only one that shows up, so he has to spend the day with Principal Edwards until they get get in touch with his parents. When Julius realizes that Chris isn't around he goes to find him, and Rochelle is a robbed on the subway.
A truck carrying weapons that were confiscated from previous crimes are now back on the streets of Miami. An old enemy of Horatio's puts the lives of two CSI's in harms way after a confiscated missile is launched into courthouse allowing Clavo Cruz to escape during his arraignment and injuring one CSI and the fatality of another CSI.