The town of Hemlock Grove is rocked when a girl is brutally murdered. A new young man in town is suspected even when the evidence suggests the murder was an animal attack.
It's homecoming at Hemlock Grove high school, but everyone in Hemlock Grove is wearing a mask of one sort of the other. Whilst at the crime scene, Peter is confronted by Roman. Olivia reveals a shocking secret while she goes back to Norman.
A new victim is discovered as Peter and Roman work together to find the killer. Dr. Chasseur helps Sheriff Sworn who thinks Peter is a suspect.
As Peter and Roman make progress in their investigation, Sherriff Sworn and Dr. Chasseur fall behind. Letha starts feeling attracted by Peter.
We learn more about Dr. Pryce's relationship with Shelley. The anniversary gala at the Godfrey Institute for Biomedical Technologies doesn't go as planned and Destiny helps Petter.
Christina's date doesn't go as planned. Also, Lisa is followed by Roman and Peter to the town's abandoned mill and make a helpful discovery.
Shelley commits an act of independence; Chasseur questions Roman but crosses paths with Olivia; Peter and Roman's friendship takes a turn.
Roman goes on a bender and attacks the Godfrey Institute. The episode centers around Roman's revelations and dreams while he is in a comma for substance abuse.
It is time for full moon again and Dr. Chasseur intends to capture the killer. Letha's and Peter's relationship is now in the open.
Roman wakes up from his coma and leaves the house. He goes back to Peter and their attempt to catch the killer during the upcoming dangerous full moon.
Peter and Lynda have to hide after their trailer is attacked by town vigilantes. Roman faces the truth about who he is and Christina disappears.
Dr. Chasseur and Olivia have a rough encounter at the abandoned mill. Peter and Roman discover the killer's true identity and Shelley finally finds out the truth about her family leading to unprecedented consequences.
Letha goes into labor as we see the whole conclusion of the killing spree and its mysteries unravel. Both, the Rumancek's and Godfrey's, are for ever changed but more horror is yet to come.