Jonas Wilde, Richard Johnson, a seasoned British agent, returns from a high‑risk operation in Guyana to his quiet life in Jersey, where he maintains a cover as the owner of a small boatyard. There he encounters his handler, Maurice Denham in the role of Peter Ravenspur, who is seen with a mysterious woman named Mari, Barbara Bouchet a figure who claims to be Ravenspur's long‑lost niece. Wilde’s world is rocked by a personal summons: a message left in The Times prompts him to travel to London and meet his superior, Canning, Harry Andrews.
Wilde, feeling his nerve falter, contemplates retirement, but Canning urges him to push forward. The mission on the table is menacing: assassinate Balin, a scientist who has defected from the East and is currently staying in England before moving on to America. Wilde accepts, even as a larger, shadowy hand seems to be closing in on him, suggesting that someone intends to kill him once the job is done. The tension tightens as Wilde enters Balin’s world and begins his dangerous ruse to gain entry. He seduces Rhoda, Diana Dors a housekeeper at Balin’s residence, to get access to the guarded site and carry out the killing.
The operation goes wrong in a way Wilde cannot anticipate: Balin is killed, but Wilde is captured and subjected to interrogation by Lucinda, Sam Wanamaker, a CIA agent who reveals a chilling pattern—one that has British operatives falling prey to enemies who seem to pull the strings from abroad. Lucinda explains that someone is orchestrating deaths of British agents by mistake and that Wilde himself has become a target because of a past misstep in Guyana, where he killed his own colleague, Adams. Wilde escapes with a growing sense of being hunted and heads back toward the sources of authority, only to discover that Canning has disappeared.
With little to go on, Wilde fuses with Ravenspur’s world once more and tracks to the Channel Islands, where Ravenspur’s network still breathes. He teams up with Ravenspur’s wife, Barbara Canning, Sylvia Syms, and they set out toward the base hidden in the Channel Islands. On a ferry, Wilde subdues Bennett, David Bauer, an associate of Lucinda, and ties up Bennett and Barbara in order to press forward with his escape. The plot thickens as Wilde learns that Ravenspur has been murdered, a revelation that shatters his sense of control and thrusts him deeper into a web of double agents.
A crucial turn comes when Wilde takes Mari aboard Stern’s boat for questioning. Brian Stern, Gordon Jackson, a fellow agent who has been bending the organization’s rules for years, reveals that he has been pulling the strings behind the scenes and that Mari serves Lucinda. Wilde and Mari escape, but Mari is killed in the process, a blow that leaves Wilde grappling with the depth of treachery around him. Returning to London, Wilde confronts another painful truth: his girlfriend Jocelyn, Carol Lynley, has been working for Stern, and her attempted poisoning nearly succeeds before Wilde outsmarts her and ends her life.
The final arc pivots on a grim, personal reckoning. Canning, who has reappeared outside Wilde’s London flat, uses a blend of coercion and leverage to force Wilde to stay within the fold of British intelligence, ensuring that Wilde remains an instrument in a treacherous game where loyalty is constantly tested and where the line between ally and traitor blurs. The uneasy truth settles in: the mission that began as a test of nerve has become a long, dangerous dance with shadows, where every friend might be an enemy and every ally could vanish at a moment’s notice, leaving Wilde to navigate a maze of deception that stretches from Jersey to London and beyond.
