Castle and Beckett Track a Possible Time Traveler [Exclusive Video]

Maya Salam
Fall TV

"Castle" channels something between "Quantum Leap" and "Fringe" on the upcoming episode "Time Will Tell," with a guy who seems to be traveling through time to warn the others. Warn them of what? Horrible events that will alter the path of human history, of course.  

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In this exclusive sneak peek at Monday's installment, it's clear that this John Doe means business. "You do not understand. We are running out of time! I need to get out of here. You have to let me go!" he yelled during a taped interrogation, which Richard Castle (Nathan Fillion) and Detective Kate Beckett (Stana Katic) are watching.

The interrogator tried to ask some questions, but this murder suspect was really in a rush. "She is in danger! Shauna Taylor. All I know is 1258. That is all they told me, OK? If I am not there to stop it, we are all dead," the mystery man said, adding that he needs to save her stat.

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But Castle and Beckett are not convinced. "Do you think by 'save,' he meant 'kill'?" asks Castle.

"He's mentally ill. He may not know the difference," Beckett says.

To find out if the man in question is traveling through time or a delusional killer (and what "1258" means), tune in to "Castle" on Monday, Oct. 21 at 10 p.m. on ABC.