John Meade Falkner 
Moonfleet 

Orphaned John Trenchard grows up in the village of Moonfleet with his aunt, entranced by the local legend of the ghostly Blackbeard, who rises each winter night to search for his lost diamond. While conducting his own hunt for the treasure, John is trapped in the church crypt and discovers the true secret of the village: smuggling. Taken under the wing of the gruff innkeeper and chief smuggler, Elzevir Block, John begins a dangerous adventure which will see him in a hair-raising chase along a precarious cliff path and deciphering a hidden code in an ancient castle.
Moonfleet is thrilling story of revenge and betrayal, of loyalty and great sacrifice, but it is above all a story about friendship..