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 rushes straight to Arlesdale End. Toby feels a little intimidated by Belle. He is happy watching the birds, but Belle has other ideas. She takes Toby to a hill which she races over, having great fun. Toby does not join in. Belle has another fun idea and takes Toby to a pig field. Toby is happy there, but Belle has another idea. She shoots water into the pigs' field, so that the pigs can play in some mud. Toby races away as he does 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 does not answer because he is not there. Belle leaves to find Toby and finally finds him in his shed. Belle feels sad and is worried that they will not be friends. As they stand quietly, Belle can hear the birds singing and has to admit that they sounded beautiful.
Toby has an idea and takes Belle back to the pig field. Quietly, they both watch the pigs snorting and snuffling. Belle does 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"