The young secret agent, Zac Darke, is back for his third mission. As always the stakes are high. An unknown bomber has begun a terror campaign in London and when an explosion on the tube leaves commuters dead and injured, Zac and his team are brought in. They are expected to work out how this terror cell operates and anticipate any future targets. The clues are scarce and they have no idea where, or when, the bomber will strike next. An unexpected source might be the break they need. A teenage hacker, Malcolm, currently detained in a young offender's institute, claims he has the answer but he doesn’t trust anyone, especially adults. Zac is sent in to question him but before they get a chance to talk he is shot by others who have a vested interest in Malcolm's capabilities. Malcolm falls into a coma and Zak must puzzle out what clues he had pieced together. There is a short timeline so Zac needs to work fast if he is to break the cipher before another bomb goes off. Who is the bomber and what is behind his reign of terror? Zak and his team are up against a ruthless and cunning foe. ( )