As he continues his investigations, Craven is visited by Emma's ghost. The fingerprints on the getaway car used by Emma's killer match those of Lowe, a man Craven arrested 10 years previously. Meanwhile, Pendleton takes Craven to meet his colleague, Harcourt, who informs him that Emma was a member of a subversive anti-nuclear group called Gaia. A team of six Gaia members, led by Emma, had broken into a low level radioactive waste facility at Northmoor; all are now either dead or missing. After Craven makes a televised appeal for information about Emma's killer, he is contacted by CIA agent Darius Jedburgh, an associate of Harcourt and Pendleton. Jedburgh shows Craven the CIA's file on Emma's activities: Gaia had become suspicious of Northmoor when a nearby reservoir had become contaminated with radioactive material, an occurrence that had also alerted the CIA, leading them to believe Northmoor was illegally storing plutonium. Jedburgh is played as a hard-bitten professional with a wry sense of humour and a passion for golfing. Along with Harcourt and Pendleton, he is keen to find the source and purpose of the plutonium. Three: Burden of Proof The police close in on their suspect, Lowe, who is severely injured in a fall while trying to escape. Dying, he tells Craven he was working with McCroon, a terrorist Craven had had convicted in Northern Ireland. Emma's boyfriend, Terry Shields, tells Craven that she was investigating a hot cell in Northmoor; he is later killed. Craven meets Harcourt and Pendleton at the House of Commons where an inquiry is taking place into the sale of International Irradiated Fuels (IIF) at Northmoor – run by Bennett – to the Fusion Corporation of Kansas, owned by Jerry Grogan. Pendleton tells Craven that he believes Bennett was behind Emma's death. Returning to Yorkshire for Emma's funeral, Craven is refused permission to seek a warrant to enter Northmoor. Returning home, he is observed by McCroon. Four: Breakthrough McCroon breaks into Craven's house intent on killing him. Craven demands McCroon tell him who he is working for but McCroon is shot by a police marksman before he can say anything. Through a contact of Mac (Struan Roger), a colleague from his time in Northern Ireland, Craven gains access to a terminal connected to the MI5 computer. He checks the MI5 records for Gaia, Northmoor, and Emma and learns that McCroon was acting on the orders