When intrepid adventurer Jim Maitland returns to England for a brief visit he meets a charming young woman named Judy Draycott who solicits his help in a perilous matter. She relates the story of her brother Arthur
- drifting in South America until he meets an old sailor who on his deathbed tells him about a hoard of buried treasure. When Arthur is shot during an attempt to return to London Maitland persuades his cousin Percy to accompany him to Lone Tree Island where the treasure is allegedly buried. But what can they do with only half a map? & can they evade the undesirables on their trail?