Written on what appears to be popular demand, this volume was published in 1956 and dedicated to four fans of the Railway Series who had written to Wilbert Awdry asking him to write a book about Percy. Up until this point, Percy had only played a minor role in the series but as the author states in the prologue, ‘we [all] think he deserves a book’. This volume elaborates on the character of Percy and introduces two new characters – Duck the Great Western Engine and Harold the Helicopter. This was also the final volume to be illustrated by C. Reginald Dalby.

​

Percy & The Signal

Percy has not changed since we met him last. He continues to be cheeky to the other engines – and after humiliating Gordon and James, the two big engines decide to pay him out. One day, Percy is careless and tells Gordon and James that he is taking trucks to the junction. The two engines seize their opportunity and pretend to be discussing ‘backing signals’. They offer to explain, but Percy declines. Later on, just outside a station, Percy comes across a signal that shows ‘line clear’ – but he has never encountered such a signal before. He immediately thinks that it is a backing signal and begins to reverse. His driver stops him in time and explains his mistake – just as Gordon rushes past with the Express. The big engines spend the night talking about signals, but Percy thinks they are being very silly. 

​

Duck Takes Charge

Percy excitedly tells the others about the Fat Controller’s plans to draft in a new engine to assist with the heavy yard duties, but they are more convinced that the lack of efficiency is due to Percy’s incompetence. This makes him cross, but he soon cheers up when the Fat Controller enlightens him that the new arrival will easily handle the work alone, meaning that Percy can help build the new harbour at Thomas’ junction. The next morning, Percy makes the acquaintance of the new engine – a handsome GWR pannier tank engine named Montague who prefers the nickname ‘Duck’. Duck settles down quickly, but the big engines take it upon themselves to order him about. Duck devises a plan to get back at them, and that evening the big engines return to find the two tank engines barring the points to the shed. The Fat Controller arrives to break up the noise and reminds Gordon, Henry and James that he is the only one entitled to give orders. When Percy leaves, Duck is left to manage alone – ‘He did so…easily!’

 

Percy & Harold

Percy is soon hard at work helping to build the harbour, but after a while he is distracted by a helicopter that occasionally flies overhead. One day, he stops near the airfield where the helicopter stands close by. Percy observes its ‘whirly great arms’ to which the stranger, whose introduces himself as Harold, explains their uses. He asks Percy if he would ever want to hover – which of course, Percy declines. Harold haughtily remarks that railways are ‘slow and out of date’ and buzzes away, leaving Percy frustrated. Then whilst later returning to the harbour with his stone trucks, he spots Harold flying overhead. He and his crew decide to race the helicopter, and the pursuit commences. Eventually, Percy arrives at the wharf – distressed that they must have lost, only to find Harold is still hovering and looking for a landing spot. The fireman treats Percy and his crew to a song to celebrate their victory. 

​

Percy's Promise

Thomas brings the Vicars Sunday School to the beach near the harbour. He tells Percy that he will be busy that evening, and that the stationmaster has agreed to let Percy bring the children home on the return journey. Percy promises to do so, but by the time he returns to collect Annie and Clarabel, heavy rain has begun to pour. Percy struggles through the storm, determined to for fill his promise – but he eventually finds himself wheel-deep in water at a flooded cutting. The water sloshes his fire and the crew must break up wood and Clarabel’s floorboards to build a new one. At that moment, Harold flies overhead and drops a parachute containing hot drinks for the crew and passengers. With a new fire and a refreshed crew, Percy fights his way through the flood and arrives at the station to triumphant cheers. The Fat Controller congratulates Percy too, and comments that despite other things, Harold admits he could never beat Percy at being a submarine.