Dickens had already achieved renown with The Pickwick Papers. With Oliver Twist his reputation was enhanced and strengthened. The novel contains many classic Dickensian themes - grinding poverty, desperation, fear, temptation and the eventual triumph of good in the face of great adversity.
The first message sent to Tom Thorne's phone was just a picture - the blurred image of a man's face, but Thorne had seen enough dead bodies to know that the man was no longer alive. But who was he? Who sent the photograph? And why? While the technical experts attempt to trace the sender, Thorne searches the bulletins for a reported death that matches the photograph. Then another picture arrives.