During a guided tour of Garre Castle, tension air-razes the air when a man is felled by an arrow after slipping away from the group. Not long after, Valerie Howett Bellamy moves into Lady's Manor, just next door to the castle, with her adoptive father Mr. Howett. Valerie is searching for her mother, Elaine Bellamy, whom she hasn’t seen in twenty years, and the quiet of the new home is soon interrupted by the arrival of John Wood, a friend of Valerie’s late brother John Bellamy who was killed in the war.
Abel Bellamy, Gert Fröbe, Valerie’s uncle, is an American with a shadowed past in Chicago and the owner of Garre Castle. He returns to London under a cloud of suspicion, and at the airport he is confronted by journalists questioning the death at his estate, reacting with a sharp, defensive edge. Across the city, Spike Holland, Eddi Arent, a persistent journalist, is pulled into Bellamy’s orbit when a man named Creager reaches out to him with something of interest. Creager contacts Scotland Yard, offering information on Bellamy, but the moment the controversial lead lands, he is shot by the elusive Green Archer. Holland’s journey leads him to Creager’s house, where he finds Creager dead and learns that Bellamy has been paying Creager 40 pounds a month—a payment Bellamy justifies as repayment for a life-saved moment.
Night brings a more personal threat: the Green Archer slips into Bellamy’s bedroom, and Bellamy awakens to fend him off with a pistol, leaving the intruder wounded. A blood-stained handkerchief bearing the initials “V.H.” is recovered, hinting at Valerie. It becomes clear that Bellamy is keeping Valerie’s mother, Elaine, imprisoned in the castle basement. Elaine clings to the hope that her son and daughter are still alive, while Valerie’s trail of clues grows sharper.
Valerie learns from Julius Savini, Bellamy’s embezzling secretary, who has been selling Bellamy information, that Bellamy has made contact with a figure named Coldharbour Smith. She follows the thread to the Shanghai Bar, a crossroads of danger where a confrontation erupts, only to be halted by Holland’s timely arrival. Undeterred, Valerie attempts a late-night break-in at Garre Castle, but Bellamy’s watchful dogs threaten her, and one is felled by the Green Archer.
Inside the Bellamy household, Inspector Featherstone—played by Klausjürgen Wussow—has secretly infiltrated the staff, fueling the investigation. Valerie is then abducted and driven to the Shanghai Bar by Lacy, a Bellamy loyalist posing as a police officer. Savini spots the impostor and follows, leading to a tense police raid on the bar. Valerie, however, has already been whisked away through a secret exit to a freighter named Calliope and hidden in a concealed compartment aboard. Savini boards the ship in pursuit but is captured, while Smith meets his end at the hands of the Archer. Despite the danger, Savini and Valerie manage to escape their pursuers.
The next day, Bellamy reveals a secret door as police close in; they investigate the cellar, only to find that the crucial woman has vanished. Bellamy then turns his cunning on Savini and his wife, trapping them in the basement. As Valerie, on the line with Featherstone, receives a ransom of risk and fear, the Archer reappears and drags her through a secret passage to Garre Castle’s dungeon. Featherstone arrives only to be captured as well, deepening the tension.
Bellamy’s motives come to light in a chilling confession: his brother once stole his girlfriend, fueling a desire for revenge. He locked the woman away and had her son sent to prison, where he endured torture at the hands of Creager. The final confrontation erupts as the police flood Garre Castle in a blaze of gunfire; Bellamy is killed by the Archer, and a catastrophic explosion by the police inadvertently destroys the Archer as well. The revelation is staggering: the dying Archer is John Wood, who is actually John Bellamy, Valerie’s brother, returned in a crusade against Bellamy, Smith, and Creager. The prisoners are freed, and Bellamy’s henchmen are scattered. The dying illusion of a single Green Archer collapses into truth: there were two Archers at work, one linked to Bellamy and one determined to bring him down. As the dust settles, Featherstone confirms that Valerie’s mother is safe, and the remaining mystery of Garre Castle begins to fade into a tense, uneasy calm.
This tale unfolds with a spider’s web of deceit, double identities, and secret passages, weaving a suspenseful tapestry of family vendettas, buried truths, and a city-wide pursuit that leaves no one unscathed.
