Morton Chapel's daughter Megan has come out of catatonia at last, but she didn't come back to life alone. Seth, her demonic alter ego, is with her, and the two of them have already wreaked bloody havoc. The hunt is now on between Chapel, who's convinced killing his daughter is the only solution, his team bent on preventing him from doing so, and Megan's grandfather, an insane, megalomaniac industrialist who believes he owes Seth his fortune...

After the SPOOKS' difficult mission in Cuba, Morton Chapel has accepted Kathryn Lennox's help in attempting to treat his daughter, Megan. The girl has been catatonic since she witnessed her father shoot her demented mother Madeleine. But Chapel speaks of possession rather than insanity; an hypothesis the rational Kathryn finds it difficult to accept. And Madeleine's father, a mining industry mogul, intends to exact his revenge from the SPOOKS leader.

Cuba, 1902. Freed from its Spanish masters by US forces four years ago, the island is still occupied by its erstwhile liberators, some of whom aren't all that eager to leave. American businessmen and politicians would like to see Cuba become a full state, while the Cuban people dream only of freedom. When people begin dying...and then come back to life, the SPOOKS are sent to investigate the possible involvement of a Cuban priest and rebel leader - a santero.

1895. Members of the East Coast elite have died under mysterious circumstances. To investigate this delicate problem, Richard Clayton - against the wishes of the President - calls upon a man named Morton Chapel for his unorthodox methods and peculiar associates. As they begin to uncover strange, vanishing marks on people's bodies, unexplained changes in behaviour and hints of widespread corruption, the team reforms around the name Ulysses S. Grant himself gave it years earlier: his SPecialists in the Odd and the OCcult - his SPOOKS.