London is a city full of marvels and mysteries, especially for someone who can't help sniffing out trouble wherever he goes. And it seemed like this was going to be a peaceful holiday. James Moriarty visits the British Museum, comes across a boy who plays the violin suspiciously well, an enormous spider, a building with a sinister past, an inventor in disguise, the largest carnivorous plant in the world, a young Irish boy obsessed with fangs, and a tropical jungle in the middle of London where no-one is safe. It's one thing after another for good old John Watson. There's only one way to find out what will happen to the Uncle Theodosius' secret diary, what a Frenchman by the name of Jules Verne is doing in London or the identity of the ghost that is said to haunt Aunt Charity's house: by reading the second installment of the adventures of young James Moriarty.