Dexter Procter, the world's youngest-ever doctor, is back for a follow-up medical mystery!

All is not well in Dexter's world. His granny has broken her leg, his friends Rupi and Otto have been expelled from school, there's a strange asthma epidemic he can't get on top of, and slimy politician Barbara Burnhall is trying to shut down everything fun at the hospital. And then his boss, Dr Marigold, goes missing!

What Dexter doesn't realize is that he and his friends are about to uncover a dastardly plot involving kidnappings, earthquakes and a demolition ball.

He doesn't know what's about to hit him... (Spoiler alert: it's a demolition ball.)