Enhanced descriptions from Syndetics:

In 1735 a team of French scientists set out on a daring expedition into the South American wilderness to resolve one of the great scientific challenges of the time- the precise size and shape of the Earth. Scaling the Andes and journeying along the Amazon, the mapmakers faced all manner of danger, while madness, disease and violent death each took their toll. However one, Jean Godin, fell in love with a local girl called Isabel Grameson. When the time came for the expedition to return to France, Godin travelled ahead to ensure the way was safe for his new family. But on reaching French Guiana, disaster struck- Spain and Portugal closed their borders and he was stranded, unable to return to Isabel. What followed lies at the core of this extraordinary tale - a heartbreaking 20-year separation that ended when Isabel, believing she might never see her husband again, decided to make her own way across the continent- a journey that began in hope but became hell on earth...
Drawing on his own experience retracing Isabel's epic trek as well as contemporary records, Robert Whitaker recounts a captivating true story of love and survival set against the backdrop of what many still regard as 'the greatest expedition the world has ever known'.