Vampire Plagues: #1 London by Sebastian Rook
The ship reached the dockside just as the sun finally vanished. Suddenly a great black cloud seemed to billow up from the deck. It swooped straight at Jack and he fell backwards off the bollard with a yell. Black creatures, large as crows, swarmed only feet overhead. They were bats, hundreds of them, the largest he had ever seen... The bats aren't the only things to leave the ship that foggy, London night in 1850. A small, frightened figure scurries down the gangplank and staggers on to the docks. Ben has been on board for the whole voyage and what he has seen will haunt him for the rest of his life. Jack befriends him and listens to his story. It's a wild, outlandish tale of archaeology, superstition and a strange, fatal sickness. As the two boys talk, little do they know what they face. London is falling into the terrifying grip of the vampire plagues and only they can prevent its total destruction...Catch Vampire Plagues - the series will be with you for life...