Lisbon, 1943. After escaping from Nazi-Occupied France, SOE agent Elisabeth de Mornay, codename Cecile, receives new orders: she must infiltrate high society in neutral Lisbon and find out who is leaking key information to the Germans about British troop movements. As Solange Verin, a French widow of independent means, she will be able to meet all the rich Europeans who have gathered in Lisbon to wait out the war. One of them is a traitor and she must find out who before more British servicemen die. Complications arise when 'Solange' comes to the attention of German Abwehr officer, Major Eduard Graf. As they get to know each other, she struggles to keep her lies close to the truth. But in a city that is filled with spies, how can she tell who is friend, or foe?