Castle (Nathan Fillion) and Beckett (Stana Katic) investigate a murder victim who worked at a primate sanctuary and whose mauled body was dumped at the emergency room in the middle of the night by a convicted killer (James Madio) recently released on parole. A talk with the convict who found the woman in the alley, before unceremoniously dumping her in front of the ER, leads Beckett and Castle to the crime scene which boasts some unusual circumstantial evidence (in the form of giant footprints) that convinces the mystery writer the crime was committed by Bigfoot.
To Beckett’s consternation, Ryan (Seamus Dever) helps fuels Castle’s wild theory by pointing to the rash of recent Bigfoot sightings and the victim’s phone conversation with a world renown cryptozoologist (Raphael Sbarge) who specialized in Bigfoot the day of her death. However, ruining their fun, Esposito (Jon Huertas) discovers a TV-show has put out a $1,000,000 reward for the proof of Bigfoot. Talking with the doctor, Beckett and Castle learn their victim was an avid Bigfoot believer and identify the obsessed big game hunter (Matthew Holmes) who was seen arguing with the victim the day of her murder. He may not be the killer, but he does inform them their victim was the one who planted the fake Bigfoot tracks in the alley where she died.
Perlmutter (Arye Gross) finds a pendant belonging to the victim’s dead roommate which she swallowed shortly before her death nearly one year after her roommate’s murder. This leads Beckett to begin searching for the roommate’s ex-boyfriend (Aaron Hill), and leading suspect in her murder. With the help of of a talented NYPD tech (Maya Stojan) and snippets of video from the night the victim died, Beckett is also able to narrow down the scene of the young woman’s murder to a two-square mile area inside a nearby nature preserve. A trip to the preserve leads Beckett and Castle to fall into a Bigfoot trap and Castle to come face-to-face with the mytical creature (or close facsimile).
Deapite discovering the identity of the fake Bigfoot and catching the missing roommate’s boyfriend, neither turns out to be their killer. Once caught the young man professes his innocence to both murders, offering a compelling case that leads Beckett and Castle straight to the one person (Albie Selznick) with the motive to kill both young women.
“The Fast and the Furriest” is a darn good mystery and a fun episode with several terrific one-liners by various members of the cast attempting to prove or discount the existence of Bigfoot. It’s always fun to see Ryan and Castle pair up accepting the more ludicrous theory while Beckett and Esposito’s cling to the far more rational possibilities. The episode also includes Castle setting a trap for someone stealing food from his apartment, which nabs Alexis with a splat of blue paint in the face. Although the explanation for the entire misadventure is rather flimsy, it does provide another cute scene to a thoroughly enjoyable episode.