Rory MacKay and his friend Duncan picked the wrong day to stop for a drink in the King's Cross tavern. Before they can even finish their first ale, Kinnear soldiers arrest Duncan and take him away to be executed at midnight, even though he has committed no crime.

Rory resolves to save Duncan, whatever the cost, but nobody in Potter's Pass will help him. With time running out, his last hope arrives in the form of a mysterious stranger, who promises Rory that he can free his friend, but could the price of his help be too high?