Belle is a large blue engine that fights fires, working out of the Sodor Search and Rescue Centre.
Belle arrived on Sodor and was introduced to Toby, who considered her a bit overwhelming. However, all Belle wanted was a friend and after putting aside their differences, they learned that they were far more similar than Toby ever would have guessed!
Later on, Belle rescued a burning farmhouse and won the close friendship of Thomas who was assisting her in taking out the dangerous fire.
Belle was sent to Ulfstead Castle to check if there were any fires to be put out during a fireworks show.
Belle, Flynn, and the Fire Brigade helped put out the fire that destroyed Last Haven.
Belle and Flynn were sent to investigate the cause of the explosion at The Man in the Hills near the Crovan's Gate Mine. Belle concludes the explosion was not caused by quarry equipment, but rather a weapon of some kind; declaring the incident to be a deliberate action by parties unknown.
Belle can be overwhelming at times, but she means well and will stop at nothing to save the lives of people and engines when threatened with the danger of fire. She also possesses an observant and analytic ability when solving cases.
- Season 2: Swashbuckler (cameo)
- Season 3: Perhaps He's Got a Corset (cameo), Samson, BoCo, and the Man in the Hills, Culdee Fell (cameo), Ice Breaker (cameo)
She may appear in Self-Fulfilling Prophecy.