The year is 1810. "Wellington needs to protect his army against Napoleon’s stronger forces in the Peninsula. His answer? The Lines of Torres Vedras: one of the greatest defensive works the world has ever seen. But for his strategy to work, the Lines must stay a secret until the French arrive. Fresh from a successful mission in Paris, Burke is sent to Lisbon. The Portuguese capital is home to French sympathisers, disaffected aristocrats, and desperate men who will do anything for money. Can Burke hunt down Napoleon's agents hidden among them?"