He again meets Michael, the younger brother, who is still unable to speak. He is suffering from amnesia - or so say two psychiatrists. Unlike Buchanan, Tweed insists the horrific murders are not random. A link must exist between the four victims. He also suspects a foreign power is involved. The tempo ratchets up ferociously. With Paula, Bob Newman and his team, Tweed travels to Marseilles, where murder is a way of life. A desperate battle takes place on a mysterious island. Escaping the city alive by a hairsbreadth, they race back home. Later they return to Dartmoor. Who is the fiendish killer? One eerie climax follows another. Could Michael be the key?