This episode opens with a man running through the park. He is being chased by something unseen. This thing slashes at him, tearing a wound in his chest. Blood is all over the place.
Dresden gets a call from Murphy and meets her at a crime scene. The victim, with head partially scalped and canine teeth ripped out is a woman. She is young, in her 20's. There is no apparent cause of death.
They find out the woman's name was Mina Watkins. She lived in Chicago. Was with her friend Heather the previous nights.
The cops find the victim's clothing nearby. They look as if they were shredded with a dull blade.
At the coroner's office the cause of death is still unknown. It is found that the woman had silver iodide in her lungs.
FBI Agent Raskin enters and she tells Murphy that the FBI are taking over the case due to the fact that there are 7 other bodies with the same MO. Dresden is told to back off.
Of course, Harry being Harry, he's more on the case now than he was before. He takes Bob to the crime scene. Bob has a special gift for Identifying blood. First they find the male's blood. He is a human, but they don't know who he is. Next they go to the spot where Mina was found. Bob places his hand on the blood and turns for a moment into a werewolf. It's all becoming clear, the reason for the silver iodide in her lungs.
Agent Raskin, questions Dresden's authenticity, calls him a parasite and tells him to leave or he will be arrested and charged with obstruction of justice.
Heather Bram, Mina's friend, is at Harry's place. He asks her to talk to him, and tell him what she wouldn't tell the police. She tells him that they were at a bar when a woman at the end of the bar started making her feel singled out and weird. She was getting a bad vibe and wanted to leave. She begged her friend to go, but she wouldn't. Heather left anyway. Mina got injured on her neck. At first it was thought to be a scratch, then it was found out to be a bite.
Back in Chicago, Mina had flu like symptoms. She got a call from a guy at the bar. Jim, from the bar, was the one who broke up the fight. Mina and Jim go out, the next morning Mina is dead.
Harry takes Heather back to the bar during the day and he sees that there is a mirror on the wall. He takes the mirror outside and asks if he may touch Heather's neck to draw energy from her. They see the night the women were at the bar. They see the woman that gave Heather the creeps. It's Agent Raskin.
The FBI come to the bar and arrest Harry, and take Heather into custody. The male agent that shows up is named Bushnell, he is the man from the beginning, the one scratched by Mina.
Harry is arrested and charged with eight counts of murder due to the fact that the FBI found silver iodide at his place.
Heather sees Mina in a dream. Mina tells Heather to find Dresden he is the only one who can save her.
Heather wakes up and tries to call for help, but Bushnell cuffs her and throws her down on the bed. Heather is beginning to change into a werewolf.
Harry is trying to escape from jail, but it doesn't look like he's going to succeed.
Bushnell admits to Heather that he is the one who killed Mina. Said he killed her like a dog, because that is what she was.
But now Bushnell is infected.
Bob and Harry are talking and figure out that there is a way to break the curse. "Kill nine, remove the sign" and 8 are already dead. So the original werewolf is Agent Raskin.
Heather gets away and finds Harry. He wants to save her. She wants to die. She also wants to kill Harry, or anyone for that matter.
Harry magically improves his sense of smell so that he can find where they were keeping Heather. It turns out not to be needed. Raskin and Bushnell are now at Harry's place. A fight ensues and Harry stabs Bushnell with a silver spike.
It seems that Bushnell is #9. Raskin is free. But she is sad that the love of her life was the one who had to die to break the curse.
Raskin is committed to a rubber room and a straight jacket.
Heather is taking an elixir to help her control the beast within. Harry wants her to stay, but she says she must do this on her own.
Bob says she'll be back. Harry just hopes that he won't have to hunt and kill her.