New York City is gearing up to celebrate Treegasm, the beloved mating ritual of a bizarre tree race, when Mark is unexpectedly tasked with handling the event. Unfortunately, one of the two trees is getting cold feet, terrified of a monogamous lifestyle. Mark must deal with the repercussions of this decision while fending off advances from Callie, who is undergoing her own strange transformation. In the meanwhile, Randall finds out that he has lost something very precious to him. Specifically, his penis.
After an unidentified pile of goo goes on a rampage, Mark leaves Leonard in charge of figuring out the creature's origin. Taking advantage of Mark's day off, Randall takes him on a road trip to south Jersey, where Mark discovers that his roommate has not "come out" to his parents as a zombie. As Leonard tries to assimilate his formless new charge into city life, Mark struggles to keep Randall's secret from his rabidly anti-zombie family.
An undocumented Werewolf is put under Mark's care after pulling an illegal "rip and chew" on an innocent civilian. Mark tries to get the victim to reconcile with his attacker, a task that is made more complicated by the fact that the victim is slowly turning into a werewolf himself. In the meanwhile, Leonard pursues his dream of becoming a famous magician like his brother Christ Angel, and Randall struggles to deal with his constant flesh cravings.
Mark Lilly, a social worker at New York's Department of Integration, is having a rough day. His department has been slashed, his zombie roommate has lost a chin, and his only remaining co-worker is a drunken wizard. On top of that, his demon girlfriend wants Mark to meet her father in Hell... literally. Can Mark do the work of 20 people and still manage a social life, or will his crazy schedule lead to unforeseen consequences for one of his case files?