The bizarre murder of the leader (Natasha Hall) of a mean girl clique at one of many private schools Castle (Nathan Fillion) was expelled from points to the unlikely suspect of an telekinesis-obsessed outcast (Hannah Marks) who believes she may have accidentally killed the bully with the power of her mind. Along with a trip to the school, which includes Castle reconnecting with the same principal (Sam Anderson) who expelled him for a stunt involving a cow years ago, Castle and Beckett‘s (Stana Katic) investigation lead them to question the victim’s best friends (Victory Van Tuyl, Malese Jow) who witnessed the killing through video from one of their cell phones.
Although Castle’s mind runs wild withe Carrie-esque possibilities, given some credence by the unexplained visual evidence and a biophysics professor from MIT (Cas Anvar) studying telekinesis, Beckett immeadiately dismisses the possibility and begins looking for other suspects. Discovering another equally unexplained telekinetic event at the school the week prior to the murder, Beckett calls on the help of Tory Ellis (Maya Stojan) to find something to prove a hoax.
As the investigation continues the case takes a bizarre turn involving several robberies of families with students at the school and a discocver of the victim’s stash inside the school library of $2.3 million German barabonds which the uncooperative parents (John Mese, Julie Pinson) refuse to discuss. Only by connecting one of the outcast’s only friends (Leigh Parker) to the victim do Castle and Beckett make a breakthrough in the case, discover the truth behind the telekinetic sleight of hand, and nab the real killer.
Despite Beckett’s refusal to accept Catle’s outlandish theory, “Smells Like Teen Spirit” does a remarkably good job of milking the concept and waiting to explain the bizarre nature of the murder while still revealing other aspects of the case and motives for the crime. By the end a reasonable explanation is given (with a nice nod at the end by Beckett offering Castle the chance to believe whatever he may wish about the truth behind the staged events) allowing Beckett and Castle to share a dance at the first prom and finally agree on “their song” for the wedding.