Barrister Ned Shepworth faces the most difficult trial of his career when he is forced to defend his own fiancee, Mona Chent, from an accusation of murdering her uncle in cold blood. A second murder clears Mona from suspicion - but makes Ned himself the prime suspect! Luckily for Ned, his friend, the erstwhile explorer Lord Prelice, is on hand to investigate the case. But who really murdered Sir Oliver Lanwin in the study of his country home? And can the answer really lie in the mysterious traditions of the native tribes of Easter Island?