Constantine Lindow is waiting for his brother Eamonn outside a central London tube station when a bus turns into the street and explodes. The next day Con is arrested as the prime suspect for the bombing. The only way to prove his innocence is to find the real bomber, and to do this he finds himself confronted by his own brother's secret life and the cold-blooded killers from his past. The trail leads Lindow half-way across the world and back to London where he tracks down a killer with a genius for encryption codes. Only Lindow can crack the code. Only Lindow can stop that telephone ringing...