Belle is a very popular engine who can fight fires by shooting water from her cannons. One day, Thomas arrives at Knapford and meets Belle, who is watching Toby trundle out of the station. Belle is sure they could be good friends as they both have bells. Thomas tells her where she can find Toby. Belle rushed straight to Arlesdale End. Toby felt a little intimidated by Belle. He was happy watching the birds, but Belle had other ideas. She took Toby to a hill which she races over, having great fun. Toby did not join in. Belle has another fun idea and takes Toby to a pig field. Toby was happy there, but Belle had another idea. She shoots water into the pigs' field, so that the pigs can play in some mud. Toby races away as he did not like whooshing water.
Belle has yet another idea and the pair travel to Maithwaite. Once there, Belle rings her bell as loud as she can. Belle invites Toby to join in, but he did not answer because he was not there. Belle leaves to find Toby and finally finds him in his shed. Belle felt sad and is worried that they will not be friends. As they stand quietly, Belle can hear the birds singing and had to admit that they sounded beautiful.
Toby had an idea and took Belle back to the pig field. Quietly, they both watched the pigs snorting and snuffling. Belle did not make Toby feel small any more. Then they go to Maithwaite where they both ring their bells delicately for the passengers and Toby introduces them to Belle, his new friend.
- Thomas (does not speak)
- The Knapford Stationmaster (cameo)
- A Sodor Brass Band Member (cameo)
- This book is based on the fifteenth season episode, Big Belle.
- In Japan this book is called "Thomas' New Friend Belle"