One morning at the shunting yards, there was trouble. Murdoch was supposed to take a heavy goods train to the Kirk Ronan, but he had broken down. The Foreman quickly called the Fat Controller. He checked his timetables, but the only engines available were Derek and Norman. The Fat Controller was worried. "Derek has terrible teething troubles and often overheats and the workmen at the Dieselworks never seem to fix Norman properly," he said to himself, but the Fat Controller had no choice and sent the two diesels in Murdoch's place.

Belle was collecting supplies for the Sodor Search and Rescue Centre as Norman and Derek were about to leave. Belle could see the two diesels looked worried as they set off and she knew why. She had to rescue them many times whenever they broke down. "Good luck, you two," she called hopefully.

Norman and Derek smiled, but they still felt nervous as they rolled out of the yard. "I hope we can do well this time," said Derek with worry.

"Actually," said Norman, "we both break down when we work on our own, but with the two of us working together, maybe nothing bad will happen."

Derek hadn't thought of that, and it made both of them feel better, but when they came to Gordon's Hill, Derek started to worry again. Hills always made his engine overheat.

"Common Derek. We can do it," called Norman and the two diesels gave their biggest effort. The top of the hill came nearer and nearer and, at last, they reached the top. The diesels felt pleased with themselves, but then, Norman's engine began to cough and sputter, and Derek started feeling very hot. Their Drivers applied the brakes as they rolled down the other side. Norman's engine sputtered again and then, Derek's engine coughed with black smoke billowing from his radiator and the cavalcade ground to a halt.

"Oh no," cried Derek.

"Not again," growled Norman.

When the Fat Controller heard the news, he telephoned the Search and Rescue Centre. "Derek and Norman have broken down," he said. "Can you send Belle to take them to the Dieselworks, please?"

"Right away, Sir," said the Rescue Centre Manager and sent Belle off at once.

When Belle arrived, she found the two diesels looking very sad. "Come on, you two," she said. "I'll pull you to the Dieselworks to be fixed." Belle buffered up to take Derek and Norman away while Hank arrived to take Murdoch's train.

Soon, they arrived at the Dieselworks. Dart was there waiting for them.

"Thank you, Belle," Derek sighed.

"Don't worry," said Dart. "Den and I will have you fixed up in no time."

But as Belle puffed away, she couldn't help but feel sorry for the diesels.

Derek and Norman sat cold in the shed waiting for repairs. They felt sorrier for themselves then they ever had before.

That evening, Dennis arrived back at the Dieselworks when he noticed that Norman, his twin, was unhappy and so was Derek. "What's wrong?" asked Dennis.

"The Fat Controller was relying on us to get Murdoch's goods train to the Docks," sighed Derek, "but we let him down."

"I'm sure you'll do better after you're fixed," said Dennis.

"Better?" frowned Norman. "We break down every time we leave the sheds. Derek keeps overheating and I can never be fixed properly."

"I don't think we'll ever be useful," sighed Derek.

That night, Dennis couldn't sleep. He had never seen Derek and Norman so down before.

The next morning, Dennis had to collect empty trucks from Knapford, when he saw the Fat Controller. He told him what Derek and Norman had said. "I'll see what I can do," he replied. Later, the Fat Controller thought hard. Then, he had an idea. "In the meantime, I'll give them simple jobs," he said to himself.

After Derek and Norman where fixed, the Fat Controller came to see them. "I think you two are in need of a change," he said. "Norman, I want you to help Stafford at Knapford Yard and Derek, you will take holidaymakers along the seaside."

The two diesels were surprised. "But sir," said Derek, "what about my goods trains?"

"Emily will do your work," said the Fat Controller kindly.

Later, Derek arrived at Maithwaite to collect Emily's holidaymakers. Duck was there. The holidaymakers were excited, but Derek was worried. "I've never pulled passengers before," he said.

"It's simple," said Duck. "Just loll smoothly and not too quickly."

The holidaymakers were soon onboard. Derek gulped and slowly rolled out of the station.

Meanwhile, Norman had arrived at the Shunting Yard. Stafford was there arranging trucks. "I'm glad you're here to help me," said Stafford kindly, but Norman was sulky.

"I've broken down even when shunting trucks before," he said.

"How many did you shunt?"

Norman thought. "About six trucks at once.

Stafford wasn't as strong as Norman and could usually only shunt two trucks at a time. Then, he had an idea. "Try shunting only two trucks like me," he said. "It will take longer, but it might help you and we'll still get the trucks in line.

Norman hadn't thought of that, so he carefully collected two trucks and shunted them onto a goods train.

Derek was rolling steadily along the seaside. The sky was blue, and the seagulls called across the water. Derek thought it was the most beautiful sight he had ever seen. As he rolled along the line, he could see holidaymakers on the beaches. A donkey was giving rides and children were eating ice-cream. Derek was so occupied with what he saw that he hadn't noticed the next station getting closer and closer.

Then Derek felt himself going slower. He was puzzled; his engine wasn't overheating.

"We're almost there," called his Driver.

Derek looked up and saw the seaside station just ahead and everyone smiled and waved at him. Derek was most surprised. He hadn't completed a job for a long time, and he couldn't help smiling.

At the Shunting Yards, Norman was feeling better too. He kept shunting his trucks two by two, arranging trains for the other engines.

At last, the day's work was done. Norman could hardly believe it, and Stafford was impressed. "I knew you could do it," he said.

"Well, I didn't think so," said Norman thoughtfully, "but I suppose I did."

When Derek and Norman returned to the Dieselworks, they told the other diesels all about their day's work. It was rare for them to complete their jobs without breaking down. The two diesels could hardly believe their luck, but what they didn't know was the best was still to come, but that's another story.