Adam Salton, originally from Australia, who is contacted by his great-uncle, Richard Salton, in 1860 Derbyshire[6] for the purpose of establishing a relationship between these last two members of the family. His great-uncle wants to make Adam his heir. Adam travels to Richard Salton's house in Mercia, Lesser Hill, and quickly finds himself at the centre of mysterious and inexplicable occurrences. The new heir to the Caswall estate (known as Castra Regis or the Royal Camp), Edgar Caswall, appears to be making some sort of a mesmeric assault on a local girl, Lilla Watford, while a local lady, Arabella March, seems to be running a game of her own, perhaps angling to become Mrs. Caswall. Edgar Caswall is a slightly pathological eccentric who has Mesmer's chest which he keeps at the Castra Regis Tower. Caswall wants to recreate mesmerism, associated with Franz Mesmer, which was a precursor to hypnotism. He has a giant kite in the shape of a hawk to scare away pigeons which have gone berserk and attacked his fields.