After observing Kenzi's clingy behavior for some time, culminating in Kenzi eating peanut sauce (which Bo knows Kenzi is allergic to), Bo realizes something is afoot. Bo storms into the Dal with Kenzi as a captive, saying that it's not her friend, but a Fae impostor. Without proof, however, and considering Bo's questionable feeding habits, Trick has her locked up for her own safety and that of those around her. Lauren and Dyson don't believe Bo's Kenzi claims. Ironically, Tamsin is the only one who thinks Bo's sane, and when Dyson escorts a weeping Kenzi to his apartment, she busts Bo out of lockdown and starts an investigation for the whereabouts of Kenzi. Dyson gets back earlier than expected, however, and Tamsin reveals her identity as a bare-skulled Valkyrie, her power of intimidation causing Dyson to doubt everything about himself.
On the run, Tamsin explains to Bo that the strange behavior of "Kenzi" - attraction to shiny objects, munching on metal - betrays her as a kitsune, a Japanese, fox-like Fae. And not just any kitsune, but Inari, a girl who traded her charm and grace to The Norn in hopes of winning a true friend. What with The Norn's craftiness, the trade left Inari hopeless of ever getting what she wanted. Tamsin and Bo head to the sorority den where Tamsin had once been hired as security after Inari went cuckoo. The sisters say some human visited The Norn and loosed Inari's power on herself. Bo knows that had to have been Kenzi, but has no idea why she would've visited the ancient crone.
Lauren and Trick are worried beyond belief when they learn that Bo's gone, but they usher the shaken Dyson home where the Kenzi doppleganger wastes no time in seducing Dyson in the most lurid way. He rejects her only to unleash her fury, and she bares rows of razor-sharp teeth. She reaches for Dyson's gun, and in his struggle to wrest it from her, he shoots her. Lauren arrives to see Dyson weeping over the body, and when she runs a test that proves the body's Fae, he wraps her in a childlike hug. There's little time for relief, though, since this means that Bo was right and Kenzi is in trouble. Dyson musters what confidence he has left and tracks Bo's trail.
On a tip from the sorority sisters, Tamsin and Bo head to Inari's den, pausing only when Bo is too weak to continue. Tamsin sees that Bo is willing to risk anything for her friend, a concept heretofore unknown to Tamsin. Considering the strength of their opponent compared to Bo's rank hunger, Tamsin insists that Bo feed on her, and they both swear each other to secrecy. They reach the den where Kenzi lies chained, starved, and terrified, and as they fight through the zombie creatures Inari posted as guards, Dyson arrives and finishes the job.
Hours later, Kenzi lies well fed and sleeping (thanks to drugs from Dr. Lauren) at the Dal. Lauren tries to apologize, but Bo can't speak to her just yet, not after the betrayal she felt when locked up and poked like just another specimen. But Lauren's worries go beyond whether she and Bo will make it as a couple: Trick informs everyone that Bo is going through an ancient Fae rite of passage called The Dawning - about 200 years too soon. Her body is changing, revolting, and if she can't fight it off, she'll transform into the most grotesque kind of underfae.
Her extracurricular activities complete, Tamsin goes to fulfill the task The Morrigan set for her: To bring the Dark Fae whom Bo attacked out of a coma and get him to confirm that Bo is guilty. Tamsin does so, but when she reports to The Morrigan, she states that the man, who now lies dead, said nothing.