Perhaps there could be a story where Thomas and Edward compete in a friendly race. Along the way, they both learn important lessons about sportsmanship and friendship. For example, when one of them has a minor accident, the other stops to help, realizing that winning isn't everything.
One plot idea could be that James and Edward get into a friendly competition to see who can pull the most cars in a day. Another could be that they have to work together to rescue a stranded train during a storm. Maybe there's a situation where James gets in trouble for being too boastful and Edward has to help him learn a lesson about humility.
They could get lost in an old, abandoned part of the railway. Thomas might be a bit scared at first, but Percy stays calm. Together, they explore the area, find old railway artifacts, and then figure out a way to get back to their normal tracks. It would be a story of discovery and courage.
There might be a fanfiction where Edward has to deal with a strange malfunction that gives him unique abilities. For example, he could suddenly be able to understand the thoughts of all the other engines. This would lead to some very interesting interactions and situations as he tries to keep this a secret while also using it to help his friends.
One interesting story could be about Edward and Emily working together to rescue a stranded train. They use their combined strength and smarts to get the job done.
One idea could be an OC engine that comes from a far - off land and has unique abilities, like being able to run on solar power in addition to steam. This engine could face challenges in adapting to the Sodor railway's rules and ways of working.
Perhaps there's a story where Thomas and Emily have to team up to win a race against some new engines that come to the island. During the preparation for the race, they discover new things about each other and their own capabilities. Emily might learn some of Thomas's quick - thinking strategies, and Thomas might learn from Emily's determination.
In fanfiction, they could face a big crisis together, like a major bridge collapse that blocks the railway. As they work side by side to fix the problem and keep the railway running, their bond of friendship would grow stronger. They might have to rely on each other's unique skills, with Thomas being fast and Edward being strong.
One plot idea could be Ian Thomas faking his death and secretly coming back to help the Liars solve a new mystery that is related to his past. Maybe he has some secret knowledge that can protect them from a new threat in Rosewood.
There could be a fanfiction where Thomas goes on an adventure outside of Sodor. He meets new engines in different lands, learns about their cultures and ways of working, and brings back new ideas to Sodor. For example, he might discover a more efficient way of shunting that he shares with Percy and the others.
Perhaps there's a magical event that only Thomas and the lady human can solve together. They might have to use their combined skills and knowledge. Thomas could use his physical abilities like speed or strength, while the lady human could use her intelligence or some special power she has to defeat an evil force that threatens their world.