Duncan Campbell wakes to discover he is imprisoned with a woman in his enemy's dungeon in the Highlands of Scotland. The disenchanted warrior hopes his last few moments on earth will be spent in the arms of the sweet-voiced Isabel. If only she will cooperate.

Isabel Douglas has no intention of obliging the crude captive. The penniless noblewoman considers herself too tall and thin to be desirable. She intends to become a nun. But first, disguised as a boy, she must deliver an important letter to Scotland's hero in hiding, King Robert the Bruce.

Together, the pair make a daring escape that plunges them into the bleak countryside in the middle of winter. In the struggle to survive, they learn the true strength of their feelings for each other. But when Duncan's animosity towards the king becomes evident, Isabel must decide between her heart and her country.