At first Sherlock is a fairly regular boy, going to boarding school. After he gets to his aunt and uncle's manor, he meets a boy named Matty who notices something weird going on in the town when he witnesses "smoke" coming out of a building a man covered in boils died in. He meets a man from the Americas who teaches him and takes him and Matty to London, in which they start to unravel it slowly, attempting to board the antagonist's ship. They end up in France where the villain is stationed. They have a fight with the villain. After the fight, they return to a port where they see a ship with a familliar name, then find out Matty and the American man sailed to France for them. Sherlocks brother then takes them back to London.
The author is Andy Lane.