Kristoffer Polaha

Riggs and Murtaugh respond to a noise complaint at a party at heavyweight boxer Ronald Dawson’s (guest star JASON DERULO) Hollywood hills home. When gunshots go off, they are drawn into a major case involving illegal gun-runners with advanced military technology. Riggs becomes personally invested in the case when he discovers one of their targets is a pregnant woman who reminds him of his deceased wife. Meanwhile, Trish (series star KEESHA SHARP) worries about Murtaugh’s health, as partnering with Riggs tests his limits.

When a famous professional cyclist is brought in after collapsing during a race, House doesn’t want to treat him because he thinks he’s lying about doing drugs.

When the headless body of a young man, along with a video camera full of documentary footage, is discovered in the DC-area woods, Brennan and Booth are called in to determine identify the year-old remains and determine if a murder was committed. The body is proven to be that of University of Virginia film student Graham Hastings, who had disappeared a year before while making a documentary about the local legend of a woman thought to be a witch who beheaded anyone who dared to look for her. In a mysteriously parallel set of circumstances, Brennan and the team find that Graham was beheaded by an axe. After examining the dark, chaotic and choppy footage from Graham’s camera, Brennan and Booth learn that two other people – Graham’s girlfriend Lori and fellow classmate Brian – were in the woods with Graham on the night of his disappearance. DNA on the axe used to murder Graham leads a shocking revelation of the killer’s identity. Meanwhile, Brennan befriends Graham’s brother, Will, when she finds out that he, too, was an orphan, but the friendship quickly dissolves when the truth behind his brother’s murder is uncovered.

The team treats a teenage gymnast who experiences complications from her intensive training. Shaun meets Lea's parents for the first time.

The winter finale, Castle and Beckett investigate the murder of a cruise ship entertainer, only to find themselves trapped at sea with the killer.