Aidan has given a mandate to the vampires who used to follow Bishop: live off of bagged blood and keep the peace with humans. Unfortunately, many of the Boston vampires are having trouble with the new rules and, even worse, Mother (the queen of the vampires) is coming to check on things.
Later, Nora convinces Sally to attend her high school graduation and Sally runs into Stevie Adkins, an old high school buddy who committed suicide before they graduated. The two of them are memorialized at the reunion along with Diane Alcott, a vapid cheerleader who was the bane of their high school existence. The reunion takes a turn when Sally confronts Diane, leading to a startling revelation and, consequently, Diane's door to the afterlife.
Josh and Nora seem to be bickering more and more around the house but, unbeknownst to Josh, the real reason is that Nora is tense about her secret: The scratch marks she sustained while trying to help Josh during one of his previous werewolf transformations. Terrified that she might have caught the werewolf curse but unwilling to alarm Josh unnecessarily, Nora volunteers to drive Josh out into the woods so he can transform.
Back in town, Mother decides that all the vampires who were turned by Bishop will be killed and that her unstable daughter will rule over Boston, with Aidan as her number two. It's therefore Aidan's job dig her up, clean her off, and get her fed on live human blood. With Mother calling all the shots, the orphaned vampires rise up and attempt to assassinate her. It's up to Aidan to stop them—although Mother hardly needs protecting.
Sally returns home from the reunion with a new trick she learned from Stevie: the ability to sleep and dream. Unfortunately, Sally's dream quickly turns into a nightmare and she wakes, horrified, to an empty house.
After Nora drops Josh off in the woods, she waits around to see if she's going to turn into a werewolf too and is greatly relieved when she doesn't. Just moments later, however, the painful change begins and, frightened, she reflexively calls out to Josh. Mid-change, Josh runs to help but is cut down mid-stride by gunshots. It turns out that Mother ordered Heggeman to kill Josh, to remove any distractions and keep Aidan focused on helping her daughter.
Heggeman approaches and takes careful aim. With Josh wounded and Nora helplessly trying to survive her first change, there's no one left to save Josh from certain death.
What goes on behind the scenes for the score of Being Human? Watch this interview with composer FM Le Sieur.
Sally makes a major sacrifice to keep two of her roommates from killing each other €“ a move that will change all of the roommates€™ lives forever.
The cast reflects on how the show has changed them over the 4 seasons.