William Gunn wants nothing more than a quiet life. After returning home from the Napoleonic wars, he accepts a position on the Duke of Devonshire's idyllic estate. Destiny, however, intervenes when his young daughter Sarah falls prey to a mysterious sickness, and Gunn must strike out once more into the unknown and search for an unusual cure-the black orchid, a plant found only in the forbidding Amazon rainforest, where the last man who saw it went insane.

Across the Atlantic, American frontiersman Nathanial Yankee has left his country and his past behind to join a new revolution, fought by General Simón Bolívar to free South America from the Spanish. Nate, however, is no hero-he fights for land, and a chance at a fresh start.

Pursued by a cruel enemy in a race against time, William and Nate must survive the battlefields of the Spanish Main, cross the snow-covered peaks of the Andes, and finally reckon with the rulers of a dying Amazonian empire. For one man, the goal is a chance to save his daughter's life; for the other, a priceless treasure beckons. If they cannot learn to work together, one of a thousand enemies will kill them (that is, if they don't kill each other first).

Unbeknownst to them, both men are pawns in a far larger game, and some secrets cannot be hidden forever …