Terrorism is afoot! McCarthy plants a bomb in a stuffed duck and "returns" it to a toy seller, saying he found it on a bench. The bomb explodes, destroying a music store and killing seven people. Regan thinks that the attack described by the decoded Hunter manifesto would have killed many more ... so was this little stunt a warning or a message?
In his lair, McCarthy tortures a woman, extracting blood and other body innards whilst Flynn, devastated that there's been no news about Abby, pops some pills. Flynn sees Regan's arm scar and realizes that she's a Hunter. Flynn complains to Jackson that he can't work with "her kind," though Jackson tells him that they trust Regan more than him.
The team receives a video message from McCarthy, greeting Flynn and warning the ETU that if they don’t give him Slavich's body, someone will die. Jackson informs his superior, Ruth Finnerman, of McCarthy's demands, but she won't pander to terrorists. Jackson wonders why the Hunters want the body when they've never demanded one before ... and Finnerman wonders why McCarthy signaled out Flynn in the video.
En route to interview Slavich's widow Jessie, Regan insinuates that Abby is a Hunter, but Flynn won't believe it. At Slavich's house, Jessie insists that her husband was innocent as Flynn plays her the now-infamous new wave song. She's repulsed by it—but only because she hates new wave! Regan's Hunter sensor tells her that Jessie isn't one. However, listening to the music tweaks Regan - she starts to "see" messages while listening to the new wave song (think how people with synesthesia "see" color). Suddenly, McCarthy calls Flynn and tells him to bring Slavich's body to a warehouse -- alone -- or Abby dies.
Flynn meets McCarthy at the warehouse. They interrogate each other and fight a lot but don't reveal much as the ETU hovers outside (they tracked Flynn). McCarthy shows Flynn a mutilated corpse, claiming that it's Abby. He's about to stab Flynn in the back when Regan rushes in and attacks him. McCarthy turns the tables and is about to kill her ... but then stops. McCarthy and Regan stare at each other in silence until Flynn calls for her. McCarthy rips off her Hunter scar and flees. The good news is, the body isn't Abby's!
At ETU, Flynn is suspicious that Regan let McCarthy get away again. Regan says that when they played the song for Jessie she saw familiar visions in her head; she believes that the clicks underlying the music are not code but the Hunter language. Listening to the track again, she explains the images she sees....which is the shape of a triangle.
Flynn plays the song for Emme, who had heard it before at a music store she went to with Abby. Flynn calls the music store and finds that it's been closed since the bombing. Flynn and Jackson figure out that McCarthy was using record stores as covers to send information and is now destroying them to eliminate data. They suspect McCarthy is set to blow up another record store ... but which one? The logo for Blue Peak Music resembles the triangle in Regan's vision!
In a seedy motel, McCarthy gets a warning from his unknown ETU mole that they know about Blue Peak, after which he has ominous shower sex with a blonde woman. Who is it?
The ETU goes to Blue Peak, where they find Jessie Slavich claiming that the place is set to blow. Jessie reveals to Flynn that Slavich persuaded her to join his cause, though she's not a Hunter herself. She says that Hunters look, smell, and sweat just like humans; they're everywhere and cannot be stopped. As Jessie activates the bomb, Regan throws herself at Flynn to get him out of harm's way ... and then angrily tears out Jessie's throat!
Flynn asks Regan if the Hunter scars/dry skin could be hidden, and she says that it could with enough lotion, as if for dry skin. Flynn goes through Abby's stuff and finds tons of lotion! Crap ... was Abby indeed a Hunter?
Meanwhile, Regan apologizes to Jackson for killing Jessie. He reassures her, but she's finding it difficult to fight her Hunter urges (which include killing) and requests a treatment. Jackson refuses because it weakens her and she needs to be strong.
In a dark alley, McCarthy caresses a beautiful woman in his vintage convertible and meets up with a giant alien thing (remember we saw this thing last episode? There are two of them, called The Quins) with a gaping mouth in its chest. He feeds the creature the scar that he tore off of Regan, saying "Tell Brother I hope he chokes on it." He's a real gem, that McCarthy.