Campion searches for the crown of a lost kingdom. Campion is asked to find documents that will prove that the Frittons are the rightful owners of a tiny Dalmatian state where oil has been discovered.

Campion visits the country house of the famous dancer Jimmy Sutane to investigate a string of unpleasant practical jokes, and falls in love. On Campion's first night at White Walls, another guest, Chloe Pye dies - though whether by accident, murder or suicide remains to be seen. Then there are more deaths, and Campion finds himself under pressure.

Influenced by his feelings for Linda Sutane, Campion refuses to believe the evidence against her husband Jimmy, and continues trying to clear his name. But when another murder occurs, Sutane's innocence becomes impossible to sustain.

Campion is drawn into the family feuds besetting the Golden Quill publishing business. One of the Barnabas family, who own the company, is found dead, leaving Campion's friend, Mike Barnabas, as the chief suspect.

Campion is determined to prove the innocence of his friend Mike Barnabas, arrested for the murder of Paul Brande, but in trying to do so he puts his own life in jeopardy.

American Judge Crowdy Lobbett has suffered several attempts on his life and has decided to leave the United States and travel to England in the hope of finding a safe haven. The Lobbett family meet Campion on board their transatlantic liner, and the Judge's son Marlowe asks him to help with their problems. Campion takes the Lobbetts to the village of Mystery Mile, where he has friends, but the Simister gang is on the Judge's trail and he soon disappears, leaving Campion and the Lobbetts with a kidnapping to solve in a hurry.

Judge Lobbett mysteriously disappears, Biddy Pagett is kidnapped and Lugg tries to warn Campion off the Simister mob investigation, but he refuses to give in.