A pair of scientists accidentally create mayhem in the North West of England by unleashing a swarm of giant radioactive wasps.

Set in post-war Britain, ten year-old Lewis Aldridge is grief-stricken as he struggles to cope with the death of his beloved mother. Left under the care of his emotionally distant father Gilbert, whom he barely knows and who quickly remarries, Lewis is forced to bury his feelings.

A modern update finds the famous sleuth and his doctor partner solving crime in 21st century London.