A Navy reservist's body is found in a beat-up car at the end of a gun range; Kasie weighs the pros and cons of buying a gun.
A mother reports her son missing and the investigation quickly focuses on a suspicious man seen in the park, but what appears to be is not, and Catherine finds herself face to face with a modern day Medea.
Brick's new teacher accuses Frankie of being overprotective when she comes up with a plan to stay on top of her kids' schedules.
It's Callen and Sam's five-year anniversary as partners. Appropriately, the pair mark the occasion with one of their trickiest undercover operations to date.
Arturo and Chloe enlist Jack's help to treat Brian, a patient who `accidentally' cut off two of his own fingers and refuses to allow a surgeon to reattach them.