When Tom Afflick heads back to Edinburgh to stay with his mother and her partner, Hamish, he begins to think that he has finally come to terms with the breakup of his parent's marriage - but a sudden accident on a country road sends him tumbling once more, headlong into the past.
This time, the book he is reading serves as the catalyst for his adventure.
The book is Treasure Island. In 1881, Tom meets Robert Louis Stevenson, a sickly young author who has just published the story as a weekly serial in a children's magazine.
Can Tom persuade him to try and publish the book as a novel or will one of the world's greatest adventures be lost forever? And is Tom going to prove to be the inspiration for some of Stevenson's best-known adventures?
One ally in Tom's quest is Catriona McCallum, the young girl he last met in 1828, now an elderly woman and an author herself.
But Tom's deadly adversary, The Plague Doctor, has once again followed him through time, and is intent on taking his revenge.
As events spiral out of control, Tom realises that this is destined to be the deadliest adventure of them all ...one that he may not even survive.