ABC’s ‘Castle’ season 5 spoilers: All eyes on Nathan Fillion in episode 5

Do you remember the episode of “Castle” that we previously told you about that could very well feature out title character as one of the primary suspects in a case? Well, we now have some more details on the hour (entitled “Probable Cause”), and it is really not looking good that Nathan Fillion’s character is going to get out of this completely and totally unscathed.

Here is the full synopsis for this episode, which was recently released courtesy of our friends over at ABC:

“While investigating a shocking ritualistic murder, Beckett and her team uncover surprising evidence linking Castle to the killing. As the evidence against him mounts, loyalties are tested. And when surprising revelations come to light, Beckett begins to wonder how well she really knows her new lover and partner of four years.”

This description makes it sound like are going to see some more trouble in the Castle / Beckett relationship, with the most surprising thing being that this is the second time that we will have seen this happening within the span of five episodes. As you likely recall from Monday night, Beckett was none too pleased about the fact that Castle used his “single” cover to the point of going on a date with an entertainment reporter after he was asked out on the air, and even though he did not make any moves on him, she still ended up on top of him wearing nothing other than a bikini.

Since we are feeling pretty sure here than Castle is not the killer (mostly because this isn’t “Dexter” and the show needs us to love the guy), how much damage do you think that this episode will really cause with the show’s primary relationship?