Magpie Mavis is a magazine story.
Mavis has been watching a bird whose nest is situated in a tree near her line. Mavis suspects the bird of stealing shiny things from the station. Her driver climbs up to the nest to investigate. In the nest he finds the stationmaster's whistle and a lot of other missing items. At the station, the shiny things are given back to their rightful owners. The Fat Controller asks if they found his watch, but they didn't.
Sir Topham Hatt's missing watch is causing confusion and delay on the railway; Henry and James arrive at the same platform at the same time! Meanwhile, Mavis is delivering Diesel fuel to the Skarloey Railway when she suddenly stops. She spots something shiny in the grass - the Fat Controller's watch! When she returns to the station, the missing watch is given back to the Fat Controller, who is so happy, he jumps for joy!
- Mavis' face proportion changes through the illustrations.
- Henry's shape changes throughout the story.