A deadly secret whispered by a dying gunrunner on a lonely road in Zambia sets MI6 agent Sam Packer on a frantic race against time. A terrorist gang has acquired a horror weapon but before Packer can discover more, the man dies. Packer is on his own, faced with sceptical colleagues and the gunrunner's daughter, Julie, who may hold the key to the secret but who also suspects it was Packer who engineered her father's death.