Secret City — Jan-Andrew Henderson

One day, Charlie Wilson finds a 200 year old diary, claiming there is treasure buried under the streets of Edinburgh.Naturally, he decides to go looking for it, aided by a mysterious young juggler named Lilly. But there's something deadly waiting below the ground.In order to survive it, Charlie must become an explorer, detective, magician, acrobat and grave robber.Then, finally, a killer.Secret City is the first book of the Galhadrian Trilogy - a completely new variation of the Arthur and Nimue legend