The chessmen of doom

"Johnny Dixon, Fergie and Professor Childermass comply with a strange will left by the Professor's brother, which requires them to spend the summer at a desolate estate."@en
"Johnny Dixon, Fergie and Professor Childermass comply with a strange will left by the Professor's brother, which requires them to spend the summer at a desolate estate where they encounter a madman bent on destroying the world."
"Johnny Dixon, Fergie and Professor Childermass comply with a strange will left by the Professor's brother, which requires them to spend the summer at a desolate estate where they encounter a madman bent on destroying the world."@en
"Professor Childermass’s brother Peregrine has left behind a huge inheritance--a mansion, ten million dollars and a cryptic riddle that might save the world from a madman. The only catch is that the professor must stay on the estate up in Maine for the entire summer. Johnny Dixon and his friend Fergie decide to come along to keep the professor company but little do they know the dangerous magic that awaits them there. As they try to decode the strange rhyme in Peregrine’s will, a powerful force is circling ever closer. Will they solve the mystery in time? Will the madman stay one step ahead of them? Who will help them save the world from destruction? This seventh book in the Johnny Dixon mystery series will have readers on the edge or their seats…or maybe hiding under the covers."@en