An interview with a federal law enforcement agency forces Beckett to reconsider her career and her relationship with Castle; a young woman’s body is found inside a flop house’s water tank.
A whistle-blower is killed and the crime scene gets sealed by Homeland Security. As Castle and Beckett continue to pursue the case, they learn that the cause of death was not a car bomb but a missile from a military drone.
When Beckett steps on a pressure-sensitive bomb, the team searches for a way to save her while Castle distracts her by talking about their relationship.
Giant footprints are discovered at a violent murder scene, leading some to believe Bigfoot is the culprit. The ensuing investigation then leads Castle and Beckett into a world of primate research, big-game hunting and myths.
Castle grows bored because he’s stuck at home with a broken leg, but things get interesting when he witnesses a murder in an apartment across the street.
A murder investigation leads to an Irish crime family Ryan knows from his days as an undercover cop, so he steps back into his old role to help solve the case, complicating his relationship with his wife in the process.
Castle and Beckett tackle one of their creepiest cases yet when a woman appears to have been scared to death by a “haunted” DVD; Castle fears for his life after he accidentally watches the video.
Conclusion. Castle seeks assistance from a shady individual to rescue Alexis after the FBI proves unsuccessful, and he learns that his daughter’s abduction is possibly tied to something more disastrous than he first realized.
Castle and Beckett investigate the homicide of an emerging reality star who was part of the cast of “The Wives of Wall Street.” Meanwhile, Castle runs into trouble as he searches for a Valentine’s Day present for Beckett.