It's 1806 and the Napoleonic Wars are raging across Europe as engineer Jack Tarver and his new wife Bethany set off for Malta, tasked with building a new road to a harbour of refuge. However, their voyage is anything but plain sailing as they battle the French and help to rescue a British spy, Mr Dover, from captivity. When they finally arrive on the island they find bitter opposition to their plans - before discovering that they are occupying a house with a dangerous secret. When Jack is attacked one day, Dover explains that the Knights of Malta have hidden a treasure from Bonaparte and that the key is to be found in Jack's house. While the British want the treasure to help finance the war against the French, the knights want to protect it for the Maltese people. And so Jack and Bethany find themselves caught up in a web of intrigue as the race to find the treasure begins.