Eureka's air conditioning system is on the blink and Dr. Stone (Richard Cox), the biology systems engineer who designed it is nowhere to be found. Allison (Salli Richardson) is concerned that with the cooling unit down, a methane buildup in the sewers might trigger explosions. Carter (Colin Ferguson) checks in with Taggart (Matt Frewer), finding him in the process of injecting a male Siberian tundra wolf with pheromones to encourage mating. Next Carter visits Dr. Stone's wife Judy (Eileen Barrett), who seems unconcerned, noting that it's not unusual for her husband to spend days in the tunnels. Back at the office, Callie (Sonja Bennett) drops by with Carter's dry cleaning just in time to witness the toilet explode, due to a methane leak ignited by Jo's (Erica Cerra) laser tweezers. A little later, Henry (Joe Morton), who's down in the tunnels trying to resolve the malfunction, calls Carter and tells him to get everyone out of Café Diem, which is about to blow. In the aftermath of the explosion, Jo inexplicably plants Carter with a deep, passionate kiss, which totally confuses them both! Meanwhile, Taggart returns to his lab to find that Wilma, the female wolf, has eaten her mate. Not good for Carter, who notes traces of the yellow dust he found near the bones in the tunnel, in the wolves' cages. On analysis, the powder proves to be a peptide spore capable of affecting the function of the eccrine gland, explaining why both Carter and Stone who were exposed in the tunnels, and the wolves who had a dedicated cooling vent in their cage have been affected. But before Allison, Stark and Carter can move to contain the pathogen, Stone gets the air conditioning system working, sending spores everywhere.