John Willoughby is being pulled between worlds. Or he is going mad, 'riding the unicorn' as his prison officer colleagues would say. It's clear to Willoughby it must be the latter. Disappearing in the middle of his prison shift from among convicts, appearing in a makeshift medieval encampment for minutes before tumbling back to the real world, Willoughby believes his mind is simply breaking apart. He finds no solace at home, with a wife who has grown to dislike him and a daughter who can barely hide her disgust. He's realised he isn't worth anyone's time, barely even his own, and falls into drinking and violence guaranteed to bring about his downfall. Except in this other world, in this winter land of first-settlers he is a man with a purpose, a man upon whom others must rely. Persuaded to kill a King so as to save a people, Willoughby finds that in another world, with a second chance he may be the kind of man he had always wanted to be after all.