Spring 1625.

Jack, a young Scottish baker longing for adventure, seizes the opportunity to work on a trading boat, the Eagle, bound for Belgium and France.

When the Eagle is forced to halt in La Rochelle for repairs, Jack discovers that his childhood friend Robin has gone missing after fighting for the Huguenots in the Battle of Blavet. Feeling obliged to seek him out, Jack's new journey takes him across northern Spain, where suspicion of both foreigners and non-Catholics is widespread. After encountering thieves masquerading as pilgrims, Jack discovers that possessing a book by Galileo can be dangerous: he needs to leave in a hurry!

Set in the turbulent world of 17th century Europe, this story draws on real historical figures in a Britain and Europe uncannily like our own.