They really have retconned Castle's character now, from someone who pretends to believe in supernatural mumbo-jumbo to mess with Beckett to someone who sincerely believes in everything. And I still say it's out of character for a mystery writer to be so unskeptical. The mentality of mystery writing is all about revealing the truth behind the illusions, showing how the tricks are done.
Although, when was the last time they even mentioned Castle's books on the show? They're still churning out Nikki Heat novels in real life, but the cross-promotion they used to get on the show is almost nonexistent anymore.
I figured out who the killer was right off the bat, although the episode surprisingly failed to follow up on the obvious clue they gave us. The gorilla was clearly a witness to the murder and was trying to communicate to Castle that one of the sanctuary employees was the killer -- most likely the one who was doing all the talking. They went to all the trouble to set that up -- not only making a point of having a character say that the gorilla was friendly and harmless, thus establishing its behavior as an anomaly, but even going to the expense of obtaining and using a gorilla costume with an animatronic face in order to create the scene -- and then never followed up on it. It's bizarre.
I would've been happier if they'd left the Bigfoot stuff out of it and had Castle trying to convince the other cops that the gorilla was the witness they needed to interview. That way he'd still be trying to convince the cops of an idea that the layperson might find implausible, but it would be one that made sense and was scientifically grounded. Indeed, I wonder if that was the original idea behind the episode, which then got rewritten into the goofier Bigfoot scenario, with the gorilla scene carelessly left in as a plot orphan.
Now that I think of it, the second sanctuary employee in those early scenes, the one who looked Native American, struck me as a character who seemed likely to have some significance in the story. The camera and direction called attention to his reactions enough to give the impression that he had something personal at stake. But he never reappeared. I wonder if this episode had not only rewrites but reshoots; it seems very awkwardly put together.
I'm very worried by the preview for next week.