James Hammond, a retired diamond trader with a past to be hidden, is searching for a new life. Taking his wife Veronica on a cruise off Norway with some friends, James meets up with an old fisherman who whisks him off to a secret Viking grotto. In the grotto, James discovers a prehistoric artefact called the Helm of Awe – a Viking magical amulet possessing protective abilities that James initially regards as mere bauble.

The cruise takes an unexpected turn when their friend Jane vanishes before boarding. Upon his return to England, James is informed that Jane has allegedly been kidnapped. Subsequently, Henry, her partner, vanishes too. Assisted by his friend Tim and police Captain Mike Ashton, James discovers that Jane, Henry, and their friends Tony and Sue are involved in a substantial financial scam scheme. When James is assaulted at his workplace, the Helm of Awe somehow protects him by creating dire illusions that frighten away his assailants.

The pursuit leads James and Veronica to South Africa, where they find the culprits. During the encounter, Tony is killed by James in self-defence after he throws the Helm of Awe at him. Veronica is shot during the shootout and survives. They settle down and begin anew in South Africa, mesmerized by its scenery and climate.

With money from the insurance claim, James and Veronica purchase a farm and turn it into a holiday resort after their gem shop burns down. They also started a wholesale business for used American wear. All is good for them with the new undertaking until political violence against white farmers places them at risk. James enters into an agreement with the local Zulu people to protect them. He navigates the risks with the help of inexplicable powers in Helm of Awe.

Meanwhile, James continues to search for Henry and Jane. By chance, he encounters them at a car dealership where they are employed under assumed names as Mr. and Mrs. Elliot. Working with Captain Van Zyl, James, and Veronica help capture the fugitives, wrapping up the case of financial crimes and earning a substantial reward.

The book concludes with James and Veronica reconciling on their farm, the Helm of Awe remaining a vigilant force in their lives as they establish a secure future for themselves and their son Richard in their adopted land.