The thirtieth addition to the Railway Series returns to the Ffarquhar branch once again, and sees Christopher Awdry tackling the rocky relationship of Thomas and Percy. The friendship of the famous comic duo is strained when a pair of ironic accidents lead to mistrust and misunderstanding. After Thomas has some separate adventures of his own with Bertie and Harold, the pair are brought back together in harmony when an emergency arises. The book was published in 1986, and was supposedly written specially for Britt Allcroft to adapt into the second television series of ‘Thomas the Tank Engine & Friends’, which premiered in the same year.

Stop Thief!
Thomas the Tank Engine feels more splendid then ever as his blue paint sparkles in the sunshine. He boasts to Percy and Toby that blue is truly the only worthy colour for an engine, but he becomes infuriated when he does not receive the response he was hoping for. The next morning, he is resting on a siding when Percy arrives with a truck of coal for the coal merchant at Ffarquhar. Thomas warns Percy to be careful of the faulty buffers at the end of the siding, but just as Percy is passing him, the truck’s side bursts open and sends coal dust flying all over of Thomas. His blue coat of paint is ruined. Percy cannot help laughing, which makes Thomas think the hiccup was caused on purpose. To make matters worse, Thomas is so dirty that he has to miss his next train. The misunderstanding sparks bitter conflict between the two engines, which escalates as the days pass – Thomas thinks that Percy caused the accident on purpose, and Percy is furious at Thomas for thinking so. Next day, Percy backs down onto the same siding for a drink. But the faulty buffers break under pressure and Percy finds himself wheel-deep in the coalbunker behind. Thomas sees everything from the platform and steams away laughing at the irony of it all – leaving Percy seething in fury. 
 
Mind That Bike!
A few days later, Thomas is sent to the Works for repairs and Duck is drafted in to take care of his duties. He becomes good friends with Toby, Bertie and Terence, and Percy is glad for someone different to talk to. Annie and Clarabel are particularly impressed with Duck’s performance, and when Thomas returns, they tell him how well Duck managed. But Thomas is so glad to be home that he forgets to be jealous. He is, however, still cross with Percy, who cleverly stays clear of him. Thomas’ crew soon learn that the Works had left Thomas’ handbrake stiff, making it seem as if the brakes were ‘on’ when they weren’t. The crew learn to take extra care – but one day, a relief man is called to stand in for Thomas’ fireman. The relief man forgets about Thomas’ brakes, and quite unexpectedly ,whilst waiting for Henry, Thomas starts off on his own. An inspector, flying with Harold, chases Thomas along the branch as he steams helplessly along the line, unable to stop himself. They finally get ahead of him and come to a station up the line. Annie and Clarabel hold back as hard as they can, slowing Thomas to a safe enough pace for the inspector to scramble into the cab as theu pass the platform. He applies the brakes properly and both Thomas and the inspector are glad that the misadventure has come to an end. 
 
Fish
The viaduct on the main line is in need of strengthening, and repairs are scheduled to take a long time. The Fat Controller does not wish to close the railway, and so main line trains have to take extra care when crossing the viaduct. This often makes them late for Thomas at the junction, and the little blue engine soon looses patience. Henry explains that if they hurried the viaduct could collapse, but Thomas is more intent on providing swift service for his passengers. At the top station, Bertie is timed to arrive just after Thomas, meaning that his passengers can go straight from the bus to their train. But they are forced to wait due to the delays. Bertie jokes that the pair will need to have another race if Thomas is late again. One day, Thomas is held up by James and cannot catch up time. But as he approaches the tunnel on the way to Ffarquhar, he spots a flash of red on the road that runs alongside the railway. It turns out to be none other then Bertie, who has broken down. Thomas happily agrees to take Bertie’s passengers, and the journey is completed safely. Both friends realise that being late isn’t such a bad thing after all. 
 
Triple Header

Percy has had enough of the quarrel and wishes to make peace with Thomas. But on the way home a hanging branch scrapes his smoke box. Thomas laughs at him, which makes Percy re-new opposition in an instant. Instead of offering peace, he decides to ignore Thomas completely. The following evening, Percy asks Toby what a ‘drip’ is, having heard a boy on the platform us it to describe his friend. Toby thinks that it is when rain leaks into an engines roof, but Thomas cuts in (tired of being ignored) and explains that a ‘drip’ is a derogatory term for a coward, a fool or a spoilsport. Percy wonders if Thomas is a ‘drip’ for preventing him from saying sorry. The next day, Henry causes a delay and Thomas is in such a hurry to get to the station in time that one of his side-rods swings up and punctures his left-hand water-tank. With water pouring from his under-frame, he can go no further. The stationmaster at Ffarquhar informs Percy’s crew of the accident. Percy is reluctant to go – but when reminded of Annie, Clarabel and the passengers, who soon sets off to the rescue (for fear that they will become drips too!). Thomas is ashamed of himself and realises that his tank made him a bigger ‘drip’ anything. The two engines make up their quarrel and re-establish their strong friendship as Percy pulls Thomas home again.