When a guilt-ridden young woman confesses to the murder of a struggling actor -- knowing details only the killer could know -- Beckett and Castle seem to have an open-and-shut case, until they uncover proof that their suspect couldn’t possibly be the killer. When a second person confesses, equally convinced they committed the murder, the team realizes the case is far more mysterious than they thought.

The episode was rated 8.02 from 1157 votes.

Continuing from the season premiere episode, 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.

The episode was rated 8.04 from 1143 votes.

The murder of a high school mean girl draws Castle back to one of his many alma maters, where he is giddy to learn that the evidence points to a surprising perpetrator - a teenage telekinetic, throwing he and Beckett into a real-life "Carrie."

The episode was rated 8.04 from 1160 votes.

Castle and Beckett's long-awaited wedding is almost here, but when a shocking surprise threatens to ruin the big day, they are sent on a wild mission filled with masked men, angry bikers and a charming ne'er-do-well from Beckett's past.

The episode was rated 8.07 from 1156 votes.

Before dying, he hands a mysterious bundle to the priest. When the bundle turns out to be a smiling baby boy, Castle and Beckett find themselves accidental nannies to the newborn. But when they determine the baby and the victim were not related, they discover that finding his rightful parents may be just as hard as solving the murder.

The episode was rated 8.11 from 1134 votes.

A desperate young murder suspect, Emma Briggs, takes hostages at gunpoint then mysteriously insists that she will only negotiate with one person: Richard Castle.

The episode was rated 8.15 from 1131 votes.

The murder of a young video store clerk takes a strange turn when the team discovers his past history as a high-level hacker. But it's nothing compared to the shock Castle receives when their investigation leads them straight to his father, Jackson Hunt.

The episode was rated 8.16 from 1181 votes.

When a Japanese ballet dancer is mysteriously murdered, Castle and Beckett's investigation into her secret life uncovers evidence that she was killed by a ninja, and now that ninja is coming after them.

The episode was rated 8.16 from 1168 votes.

When Castle and Beckett discover that the victim of a building fire was actually shot to death, they get on the trail of a serial arsonist turned murderer. Meanwhile, Ryan's wife, Jenny, goes into labor, but disaster threatens to ruin the joyous moment.

The episode was rated 8.21 from 1180 votes.

Alexis enlists Castle’s help on an Innocence Review case to prove that a death row inmate, Frank Henson, was wrongly convicted. With only 72 hours left before his execution, Castle and Alexis (with help from Beckett) urgently investigate the original murder, only to uncover explosive secrets that may seal Frank’s fate.

The episode was rated 8.21 from 1120 votes.

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 episode was rated 8.21 from 1217 votes.

Beckett is recruited to assist on a Narcotics investigation, but a routine mission turns deadly when an undercover operation goes array. To survive, Beckett must engage in a battle of wits against some of the most dangerous men in the New York underworld – including a powerful enemy from her past.

The episode was rated 8.21 from 1188 votes.

A grisly murder investigation leads Castle and Beckett to a suspect who claims he's traveled back in time to stop terrible events from unfolding, events that will change the course of human history. Is he simply a deluded killer, or is it possible that he's telling the truth?

The episode was rated 8.38 from 1169 votes.

Castle and Beckett arrive at a crime scene to discover that the female victim bears a shocking resemblance to Medical Examiner Lanie Parish. As the team tries to make sense of this mystery, they realize the killer may be targeting detectives of the 12th Precinct. Dr. Kelly Nieman, an exclusive Manhattan cosmetic surgeon who draws Castle and Beckett's interest because of her connection to the victim.

The episode was rated 8.38 from 1162 votes.

A secret investigation conducted by Beckett related to her mother's murder goes awry when a man she has been surveilling is killed. When evidence links Beckett to the victim, she and Castle become the targets of a manhunt that puts both of them in grave danger.

The episode was rated 8.42 from 1177 votes.