Vampire Plagues series

Vampire Plagues is a series of six books written under the pseudonym Sebastian Rook. The first three books were written by Ben Jeapes, the last three by Helen Hart. The books focus on the adventures of three children, Jack Harkett, Benedict Cole & Emily Cole, taking place in 1850. It can also be found as the series Vampire Dusk.

London, 1850
Twelve-year-old Jack Harkett is a street urchin living on the London docks. So when a merchant ship sails into port at twilight, he recognizes it for what it is: an opportunity. But Jack had never seen a ship quite like this one. Aside from a flock of enormous black bats that flies from its hull, there's only one living soul on board - a young stowaway named Benedict Cole. Jack and the wealthy, educated Ben have little in common. But once Jack hears Ben's hair-raising story of an ill-fated expedition to Mexico - and the strange sickness that has followed him back - the two boys find themselves on the same side of a deadly struggle. With no one to turn to and nothing to rely on but their wits, they face a plague the likes of which London has never seen before....

Paris, 1850
Jack wants to believe it was only a dream, that the vampires are gone, that they have been banished by an ancient ritual that sent their leader to the depths of hell. But he is not so sure. That voice still echoes in his mind - the voice of a vampire god promising to return. Jack's friends, Ben and Emily, say it is just his imagination, and he desperately wants to believe them. While Victorian London may be safe, a strange sickness is raging in Paris. A familiar illness that leaves its victims drained of blood. It seems the vampires have moved on with their lives, and the fight must follow them....

Mexico, 1850
Camazotz has managed to secure nearly all the pieces of a powerful amulet that will give him untold strength. There's only one piece still to be recovered, and it is in Mexico, the seat of Camazotz's power. Now, Jack, Ben and Emily are caught in a race to reach the Yucatán Peninsula. They are one step ahead of the vampire god and his evil servants, but the three friends know that Camazotz will not be far behind. Their only hope is to find the final, missing piece of the amulet before the vampire god does. And they will get some help from a most unexpected source. But the jungle is a dangerous place, where things are not always as they seem. And fighting Camazotz on his home turf will prove to be their greatest challenge yet.

Outbreak
From the back cover "Ben, Emily and Jack are looking forward to a quiet Christmas back in London, celebrating their victory over the vampire hordes. But it is not to be. Camazotz may have been vanquished, but a new plague of terror is gripping London’s streets. The undead are rising, and they’re hungry! This new evil is even more dreadful than the last, and its vile creatures seem impossible to kill. Can the trio hope to defeat the foul menace that is looming over their city?"

Epidemic
From the book: "Christmas comes to a devastating end for Jack, Ben and Emily when they discover that Ben is infected by the vampire plague. But when they race to Poland to find a doctor who is rumored to have developed an antidote, they find it in the grip of a vampire epidemic of monstrous proportions. From the city of Warsaw to the snowy forests and villages, the country is swarming with the undead ...and this time there seems to be no cure."

Extermination
From book back: "A hundred snarling lampirs had gathered across the pathway. Grey river-mist around their feet. Somewhere a wolf howled, and a bat dives to flit low across the surface of the water. And Jack saw, with a sickening certainty, that there was no way past the lampirs... They were trapped. Ben, Jack and Emily are journeying into the Polish mountains, desperate to end the lampir plague that is draining the country. If they destroy the monstrous Count Lampirska, evil founder of the lampir clan, then Poland's dead can rest at last. But the lampirs will do anything to stop them..."