Maxwell’s dad is an engineer. He works in a factory designing engines for jumbo jets, using powerful computers. At the weekends he builds model trains and plays with them on a track in the loft. Maxwell thinks his dad is the cleverest person he knows.

Maxwell’s mum makes bowls, plates and vases out of clay at the local college. She sells them in her friend’s shop and at craft fayres in the summer. Maxwell thinks that her pottery is very good, but she does tell him off a lot when his experiments go wrong.

Joanna is Maxwell’s little sister and likes playing with dolls. She thinks that he’s very clever, and she is always interrupting his experiments to see what he's doing. Maxwell finds this very annoying.