Alexis enlists Castle's help on an Innocence Review case to prove that a death row inmate, Frank Henson (guest star James Carpinello, "The Good Wife"), was wrongly convicted.
When a famed relationship therapist is murdered, it appears that her access to the secrets of her elite and powerful clients led to her death.
In "Dreamworld", Beckett races against time to find a stolen toxin capable of killing tens of thousands of people. To make matters worse, Castle was exposed, leaving him with less than 24 hours to live
"In the Belly of the Beast" an undercover mission goes array putting Beckett's life in Danger.
In "Time Will Tell", a murder suspect claims he's a time traveler from the future who's trying to prevent disastrous events from unfolding.
Castle and Beckett investigate the death of a young girl who appears to have been killed with telekinesis.
In "Dressed to Kill," a young woman's murder sends Castle and Beckett into the world of cutthroat world of high-end fashion.
A desperate young murder suspect, Emma Briggs, takes hostages at gunpoint then mysteriously insists that she will only negotiate with one person: Richard Castle
Last season ended with Beckett wrestling over whether to take a high-profile job in DC -- a dilemma made more complicated when Castle proposed to her. In the Season 6 Premiere of "Castle," Castle and Beckett will deal with the consequences of their decisions against the backdrop of a high-stakes investigation.
"The Greater God" — The death of a Wall Street puts the team on a collision course with Gates' sister.