This week's episode of Castle posed an interesting question: Would you break your love out of prison?

Next week, however, the inquiry gets far more dangerous: Is the Tripler Killer back?

Castle and Beckett are faced with this possibility after a dead woman leaves clues indicating that the man also known as "3XK" has returned after a four-year hiatus. See how this all comes about in the official ABC preview below:

[video url="http://www.tvfanatic.com/videos/3xk-preview/" title="3XK Preview"] [/video]

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.