During World War II, a British corporal named John Bramble, the sole survivor of a tank crew, stumbles across a desolate hotel in the Libyan desert after escaping a German assault. Disguising himself as the recently deceased waiter, Paul Davos, Bramble plans his next move. The hotel’s owner, Farid, hesitantly agrees to the subterfuge to protect them from the Germans who soon arrive to occupy the establishment. Among the Nazi ranks is Field Marshal Erwin Rommel, who uses the hotel as his headquarters. Rommel, believing Bramble to be Davos, involves him in his plans without suspicion, giving Bramble a unique opportunity to gather intelligence.

As Bramble delves deeper into his role, he learns of coded secrets referred to as the "Five Graves." Realizing that uncovering their meaning could provide a critical advantage to the Allies, he works covertly to decipher the clues while maintaining his cover. Complications arise when Mouche, a French chambermaid with her own agenda, discovers Bramble’s true identity but reluctantly agrees to assist him. As the stakes rise and Allied forces draw nearer, Bramble faces mounting risks in his mission to thwart Rommel’s grand strategy and turn the tide of the war.