First new book of the Railway Series for a decade following Tramway Engines, written by the son of the original author for his own son Richard.  Christopher was encouraged to seek publication from his father following his approval of the stories, focusing on Thomas, Duck and Percy as he brings the Railway series back to life, and Christopher makes his style of story writing his own.

Stop Thief!
In the first story Thomas finds himself in hot pursuit of a robber who has stolen silver ware from the Station Master’s house the night before, as well as his car.  They find the thief in the stolen car going along a road close to the line, and give chase to the villain, knowing they won't catch him however, they make canny use of quick thinking and get a signalman to telephone the police.  Thomas is hailed a hero for his brave actions by the Fat Controller as the goods are soon recovered and the thief is apprehended by the Police!
 
Mind That Bike!
Percy's friend, Tom Tipper the Postman, has lost the use of his van and had it replaced by a pedal bike, which he finds difficult and awkward to deliver the post with.  But one day when he’s called away, some unruly boys decide to use it without Tom's permission, and leave it on the rails.  Percy crushes the bike under his wheels as he moves off, as his Driver didn't know about the bike ahead of them, and leaves Tom with nothing to carry the mail with.  However, as a result of the accident, the Postmaster gives Tom a new van instead of a bike as a replacement, and Percy feels better about the situation, feeling in some way, he helped!
 
Fish
When Henry is back pulling the Flying Kipper, Duck is been given the job of pushing him up the hill at Gordon’s Hill.  All seems to go smoothly until Henry’s van loses a tail lamp and Duck loses sight of the train in the darkness, and when Henry slows down, disaster strikes as Duck hits the train, causing damage to his front end.
 
Triple Header

Thomas boasts to Gordon that tank engines are always full of energy compared with the big engines, after Gordon returns home after pulling the Express feeling exhausted.  But when Thomas, Percy and Duck are called upon to do a Triple-Header with the Express when both Gordon and Henry are unavailable, the three engines begin to prove Thomas wrong when the three engines find the heavy train hard to pull, even collectively.  By the end of the journey, Thomas, Duck and Percy are living proof that his comment was very wrong indeed, as Gordon can see for himself, and duly lets Thomas quietly know!