A rock concert at Thames University is plunged into panic by the grisly killer werewolf! Screams fill the air, as people rush to escape the monster’s clutches. Where are the police? a fearful students asks, while another points out that they need Captain Britain. But, at the moment, the British superhero is busting out of a dungeon cell at Darkmoor Castle, with other problems on his mind – namely finding the lovely Courtney Ross, before the Black Baron’s fangs turn her into one of the living dead.
A frantic alarm brings the police to the rock concert, Chief Inspector Dai Thomas in the lead. They try to gun the beast down, but find that the hail of lead has no effect. Thomas muses that the old stories must be true. Only a silver bullet can stop a werewolf. In savage fury, the werewolf seizes Thomas, only to hurl him straight back at the oncoming police, slamming into them with knock-down force. He flees though the door.
Back at Darkmoor Castle, Captain Britain has rushed to the room where he saw the Black Baron bending over a sleeping Courtney. He finds no fang marks on the sleeping girl’s neck and, relieved, tries to wake her up. But, as he lifts her in his arms, she turns into a hideous old hag before his eyes. Suddenly, claws clutch him in a viselike grip. She isn’t Courtney, Cap shouts out and, with his denial, the throat-grip relaxes and the cackling hag fades away. Another of the Black Baron’s magic tricks. Cap flies downstairs, demanding answers from Hugo, the Castle retainer. He drags him up and flies outside with him, threatening to drop the man should he refuse to talk.
Back in London, the police are chasing the werewolf through darkened streets into Regent’s Park, where the Werewolf heads for the zoo’s wolf cages and frees the animals by ripping apart the cage bars with his bare hands. The police are forced to take care of the wolves, as Captain Britain joins the fray, much to Thomas’ displeasure.
Captain Britain faces the werewolf and fends of his attack by swinging his star scepter like a bat. But, suddenly, a four-legged wolf leaps at his “brother’s” enemy, enabling the werewolf to grab a nearby bench and hurl it at the hero. The makeshift missile thuds home against its target with a stunning impact that would break the back of a lesser mortal and the British hero goes down.
Seconds later, though, he’s zooming up and after his fearsome quarry, while the werewolf bounds through the shadowy bystreets and alleys. Presently, the creature comes in sight of Tower Bridge and, on the Bridge’s northern approach, it leaps aboard a passing lorry… only to jump next instant from lorry to bridge tower.
But the move spotlights the werewolf in the glow of the full moon and Captain Britain zeroes in. Hand to paw, the two opponents grapple for each other’s throats. Suddenly, they topple toward the Thames and the star sceptre slips from Captain Britain’s hand. With his lightning-swift reflexes, Captain Britain dives after it and his keen senses enable him to spot the precious staff under water.
When the Captain surfaces again, there’s not sign of the creature and he believes the creature to have perished. He decides to fly back to Darkmoor to find Courtney and only a passing barge hand notices the bat that flutters off under the Tower Bridge.
