Rheneas and Skarloey are busy bringing birdwatchers to the lakes and hills of the Skarloey Railway to look for a rare bird. After days and days of searching, the bird is nowhere to be seen.
Meanwhile, Rusty is checking the tracks when he sees something in the sky! As the huge "bird" disappears behind a cloud. Rusty races to Top Station. Once there he tells Rheneas, Skarloey, and all of the birdwatchers about the huge "bird". The birdwatchers are intrigued and ask Rusty to show them where he saw the bird. So that is what he does and there is the "bird". The birdwatchers inform the engines that it is not a huge bird - it is a hang-glider!
Then the birdwatchers spot something amazing - the snowy owl they have all been looking for! They would have never found it without Rusty's help.
- Rusty's 'front' is orange instead of black.
- Skarloey and Rheneas' running board are painted white.