But do not fear. As usual, there is a plucky young hero waiting in the wings to save the day - and thousands of grateful citizens.

Ivo Moncrieff is on his first trip to Britain's capital to spend Christmas with his aunt and uncle while his parents are on an expedition to South America.

One day, while he is waiting for a train, a stranger pushes an object into his hand seconds before being murdered. Amid the chaos, Ivo leaves the station and goes to his relatives' house. But he does not tell them about the mysterious object now in his possession.

However, Ivo knows that someone will be looking for him - and what the dead man gave him.

Womack builds up a small but strong set of characters and a solid setting in this fast-paced thriller.

Ivo becomes friends with a couple of local teens, Miranda and Felix, and the three of them attempt to find out the identity of the murdered man and who, or what, caused his death.