If there’s one thing Rick Castle (Nathan Fillion) likes it’s a good conspiracy, and no conspiracy beats the furriest of them all: Bigfoot. The urban legend that has persisted for many years is the focus of tonight’s Castle, though much like the Bigfoot legend itself, this episode is all about misdirection.

The case centers on the brutal death of Ann Cardinal, an evolutionary biologist whose side hobby was tracking down Bigfoot. Unlike those hunting for sport or to win prize money from a local TV monster show, Ann’s interests were deeply rooted in her Native American cultural beliefs that see Bigfoot as a protector, not predator. Her work in that field garnered the attention of a number of potential suspects, including Dr. Darrell Meeks (Raphael Sbarge).

It’s good to see Sbarge doing work outside of the Enchanted Forest and he plays the role of the bumbling, geeky doctor who honestly believes in the existence of Bigfoot. The backstory outlined for him at the front of the episode sets up the back half perfectly. That he is the one who built the trap in the woods that captures Castle and Beckett (Stana Katic) along with a faux Bigfoot suit is topped only by his excitement in describing the noise evidence he heard that Bigfoot was nearby; noises that Castle was making to attract Bigfoot.

Oh, and the good doctor stumbled over the murder weapon, as well.

Recently, the writers of Castle have been doing a great job of hiding the real killer amongst a number of plausible red herrings and “The Fast and the Furriest” is no different. Ann’s co-workers and professors are interviewed, along with a Bigfoot bounty hunter and, of course, Dr. Meeks.

Slowly, however, the focus hovers around Kurt Wilson (Aaron Hill) and it’s here the story shifts from Bigfoot to murder – Ann’s roommate’s murder to be precise. Wilson was the key suspect in that crime and the more they look into it, the more it seems likely that Ann was killed because she got to close to finding Wilson again and turning him in.

Again, the writers are getting clever and, as it turns out, Wilson is no more a murderer than Meeks is Bigfoot. Yes, he was the main person of interest in the murder of his girlfriend a year ago, but it turns out that Ann is the only person who believes he is innocent. It was he who brought Ann to the woods, not the Yeti, and the last he heard from her was that she was close to finding the killer.

In the end, all clues point to Professor Devlin (Albie Selznick), who taught both Ann and her roommate, Justine. He had been stalking Justine after she took one of his classes, and when she went to the Dean, he silenced her for good. Fortunately, Ann found the pendant Devlin had taken and because of her persistence, he’s caught and Kurt Wilson is given a new lease on life. A life he plans to devote to proving the existence of Bigfoot.

Episodes like this are fun because they explore the beliefs of the main characters. Esposito (Jon Huertas) and Kate are the pragmatists, insisting that the case remain focused on the human side of the story. Meanwhile, Castle and Ryan (Seamus Dever) are all too happy to bend the evidence to fit the Bigfoot myth.

Kate and Castle’s pillow talk is a great character moment. The side story with Castle and food thief, Alexis (Molly Quinn), is a fun one too. Looks like the tension will be back in full force next week when Kate and Castle’s lives are once again on the line.

Castle airs @10pm on ABC.