Kemp blamed himself: he should have kept more closely in touch with his younger sister. Now it appears that Lorna has gone off to Colombia with a man named Roberto Vargas. But Kemp finds the story hard to swallow - there's something fishy about it. Apparently there had been a party at the Essex house of Barton Sanger, but when Kemp goes there to make enquiries, Sanger is either unable or unwilling to provide any information. After an attempt on his life and some revelations from a character called Mekkle, Kemp has only one purpose in mind: to find Vargas and kill the fat man from Colombia.