Grad student Eric Cord becomes infected with lycanthropy after his friend turns into a werewolf and attacks him. Now, Eric and his girlfriend are after the monster that infected his friend, and a tough cowboy bounty hunter pursues Eric.
Eric tracks Skorzney to a shadowy boatyard and begins to keep a journal. He steals a revolver and gets some silver bullets, hoping to kill Skorzney to end the curse. But Eric is captured by sailors who plan to turn him over to Alamo Joe.
Eric, wounded by Alamo Joe, is saved by a young boy fascinated by monsters, werewolves in particular. But things get hairy when Mom's abusive boyfriend starts slapping her and her son around and Eric saves the day.
Eric locates Otto Renfield, a crippled old sailor who knows Skorzeny and promises to help Eric find him. But Renfield betrays Eric and traps him in the hold of his ship for Skorzeny.
Eric seeks help from college professor Dr. Victor Degoethels who has written a book about werewolves throughout the ages. But Alamo Joe has already warned him about Eric and his crimes.
Tired and worn out, Eric accepts the hospitality of an old man at his home in the woods. He becomes attracted to a young woman named Margaret, but he fears that he may be responsible for a series of brutal murders in the area.
Eric meets a good witch in the woods who offers to cure him. She gives a love potion to a girl who's boyfriend dies after taking it. The boys dad, blaming her, shows up with his buddies and burns her house down, with her in it.
Eric, working in a Mom-and-Pop diner, has to save the day when a gang of bikers show up to terrorize Mom, Pop, and a pretty customer. Soups on, werewolf style.
Eric sets out after Janos Skorzeny following the rumors of a Bigfoot sighting. After a ferocious battle with a stronger werewolf, Eric finds sanctuary in the home with a woman named Mary who has a strange and supernatural secret of her own.
Eric seeks safe haven in a monastery, but the monks there have secrets of their own. In the past, the werewolf Skorzeny paid a visit to the monastery and turned at least one of the monks.
Alamo Joe catches up with Eric in a small town jail, then attempts to grill him about his lycanthropy. Eric tells him he still has hopes for a cure, but later turns into a werewolf, escapes from the jail and Alamo Joe is forced to kill him.
With Eric apparently dead in the morgue, Alamo Joe recovers from his wounds in the hospital and reevaluates his life decisions. He fears he was bitten and will now become a werewolf. Eric returns from the dead and escapes from the morgue.
On Halloween, Eric sees the pentagram appear on his hand and knows his transformation into a werewolf is imminent. He locks himself in an abandoned house, not realizing that a disfigured recluse still lives there.
Taking a job with the railroad, Eric meets and befriends a former prize fighter who was a childhood idol of his, who is on the run from the mob after he refused to throw a fight. But a bar-room brawl draws the mob's attention to the man.
In a run down hotel in a town where a slasher has killed 7 people, Eric checks in after inquiring about Skorzeny. He meets several people staying at the hotel, including a man in black who reveals that he is also werewolf born in 1468.
While working as a grounds keeper on a large estate owned by a kindly old lady, she is brutally murdered in her own home. Both her granddaughter and granddaughter's husband implicate Eric. But Eric knows he didn't do it and knows who did.
Eric is kidnapped by a corrupt Southern politician who is dying of cancer and wants Eric to cure him and make him immortal by turning him into a werewolf.