While investigating a subway worker's murder in Central Park, Castle and Beckett unexpectedly uncover a boy's abduction.
When Beckett and Castle respond to an 'officer down' call, they discover the victim is actually a male stripper dressed as a cop.
When a beautiful woman is found dead, the evidence indicates a notorious serial killer known as The Triple Killer.
An unknown woman falls out of a casket along with the original deceased when pallbearers lose control of the casket at a funeral; the investigation takes Beckett and Castle into the world of amorous, bed-hopping physicians.
A young mathematician is shot with a 200-year-old bullet, inspiring wild theories by Castle about a time-traveling murderer.
When a coded document attracts Castle's attention, Beckett must steer the case back to the violent felons who populated their victim's world; when Beckett's ex-partner arrives, Castle must watch the relationship become romantic.
Beckett and Castle search for a psychic's killer while debating the existence of extrasensory abilities.
When Beckett and her team burst into an apartment on a murderer's trail, they see Castle standing over a dead woman's body holding a gun; Beckett arrests Castle as he asserts his innocence.
Successful New York mystery author Richard 'Ricky' Castle get permission from the mayor, as a personal favor, to seek inspiration and factual documentation by tagging along with a detectives team.
Castle and Beckett investigate what seems to be an intelligence operative's assassination; Beckett's relationship with Demming strains her relationship with Castle.
A robbery-homicide prompts Beckett to invite Demming to assist on a case; the investigation becomes a competition for Beckett's attention.
A well-known chef is found frozen to death in the kitchen of a New York restaurant; Castle shares an attraction with a former classmate of Beckett's.
Castle and Beckett find that Esposito has a personal connection to a suspected killer; Beckett connects with an attractive new detective.
When talk show host Bobby Mann mysteriously dies, Castle is convinced that there was foul play; a guest on Bobby Mann's show seduces Castle.
The investigation into a museum curator's death takes a bizarre turn when Castle and Beckett learn he is not the first member of a recent archaeological expedition to die.
The serial killer, still at large, taunts Castle, Beckett and Shaw to catch him.