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.

Con is determined to prove his innocence, but the only way he can do that is to find the real bomber. As he digs deeper, he finds himself confronted by his own brother's secret life - and the cold-blooded killers from his past.

The trail leads Con halfway across the world and back to London, where he tracks down a killer with a genius for encryption codes. Only Con can crack the code. Only Con can stop that telephone ringing...