Mexico is famous for its rich culture, ancient ruins, dazzling beaches, and spicy cuisine. But there is a darker side to America's southern neighbour, with vicious gangs dealing in drugs, extortion, money laundering, human trafficking and contract killings. Jack Nightingale came across his fair share of villains when he worked for the Metropolitan Police in London. But nothing could prepare him for the evil that was waiting for him when he crossed the Rio Grande river and entered Mexico - an evil that is hunting for an immortal soul. A very special soul.