Thomas and Mavis went to tell steam engines and Diesels all over the island to meet at the coaling plant, a chance and hope for them to work together and get the new Sodor Airport built on time. When Thomas went over to tell Diesel 10 about the meeting, he got scared to his wheels. Not sure if Diesel 10 would want to help the steam engines anyway, due to their difficulties in the past, Thomas sped away as fast as he could.

Construction of the airport was almost complete when a tower collapsed, cracking the runway and blocking the tracks. With Harvey too far away to clear the line, Thomas took a chance and decided to ask Diesel 10. Convincing his former archenemy that helping the other engines would prove how useful he was, Thomas returned with help to clear the line.

In The Great Discovery, Diesel 10 and a number of other Diesels later waited in the quarry yard to hear if Thomas had been found in the days leading up to the reopening of Great Waterton.

At the end of Misty Island Rescue, unbeknownst to the steam engines, Diesel 10 was seen on a bridge overlooking the Sodor Search and Rescue Centre threatening them.