Nadia writes down everything that happens at the Marrow Lane allotments. So she's the first to spot it: Mr. Okafor's giant champion pumpkin moved overnight. Not gone, just sitting three plots away in Mrs. Pratt's strawberry bed, plump and shiny with dew. By morning both grown-ups are yelling at each other. Nadia opens her notebook and starts writing.

Nadia decides to study the pumpkin itself. She crouches in the strawberry bed and looks close. There are faint drag marks in the dirt and a single muddy footprint near the leaves. She measures the print with her ruler. It's small. Way too small for a grown-up.

Nadia follows the little footprints. They lead across two plots, past the shed, and stop at a gap in the fence behind the Lim family's garden. A red toy wagon sits there, with a smear of pumpkin dirt on the handle. Nadia writes down: 'wagon = how it moved.'

Nadia knocks on the Lim family's door. Little Theo answers, and his face goes bright red the second he sees her notebook. 'It was a game,' he whispers. 'Me and Priya wanted to see if the grown-ups would notice.' Nadia walks him over to apologize, and Mr. Okafor laughs and forgives him. Solved.