Faced with appalling weather, and pursued by an overwhelming French army led by Napoleon himself, the very survival of Britain's army is at stake.

But while the 106th Foot fights a desperate rearguard action, for the newly promoted Hamish Williams, the retreat turns into an unexpectedly personal drama. Separated from the rest of the army in the initial chaos, he chances upon another fugitive, Jane MacAndrews, the daughter of his commanding officer, and the woman he is desperately and hopelessly in love with. As the pair battle the elements and the pursuing French, picking up a rag-tag band of fellow stragglers along the way - as well as an abandoned newborn - the strict boundaries of their social relationship are tested to the limit, with surprising results.

But Williams soon finds he must do more than simply evade capture and deliver Jane safe and sound to her father. A specially tasked unit of French cavalry is threatening to turn the retreat into a massacre, and Williams and his little band are the only thing standing between them and their goal.