Boundless McLennan, a young Scottish printer, is sentenced to indentured servitude in the American colonies for the crime of seditious libel. Upon landing in the New World, he escapes and learns of a marvellous beast inhabiting the far western plains.

A trapper takes Boundless under his wing and seduces him with tales of endless grasslands beyond the Alleghenies where the buffalo are rumoured to be so plentiful that 'Jehovah himself could not count the heads'. Together, they set out on an epic adventure across a thousand miles of wilderness full of dangers-from bandits, wild animals, hostile Indians, and a brutal war between England and France for possession of the New World.

Despite the perils of the journey, Boundless is determined to lay eyes on the mysterious creature that beckons him to his destiny on the vast, windswept plains.