Proud Puffer is a magazine story.
One night, Peter Sam is working late as he passes an old mine and cottage. Peter Sam thinks the place is rather spooky with the wind whistling eerily all around. Peter Sam races, scared, towards the shed at the Top Station. Peter Sam parks between Rusty and Duncan in the shed and is very pleased to be there. Peter Sam explains about the old mine and the cottage. Duncan teases Peter Sam and assures him that the cottage and mine have been abandoned for years. Peter Sam thinks Duncan is being rather rude.
The next evening, Peter Sam passes the cottage and mine again. Suddenly, he sees a mysterious light inside the cottage, but then it vanishes. Peter Sam decides not to tell anyone; Duncan would only laugh at him anyway.
In the morning, the Fat Controller arrives with a policeman. The policeman tells all the engines that some thieves have robbed Wellsworth Bank and they are hiding nearby with stolen money. The Fat Controller instructs all of his narrow gauge engines to keep a look-out for anything unusual. Peter Sam tells them about the strange light in the abandoned cottage.
The policeman phones urgently for help and more police officers drive to the Top Station. Peter Sam then takes them, along with the Fat Controller, to the mine. Once they are there, Peter Sam slowly pulls to a halt and sees that there is a light in the cottage once again. The policemen hurry over and arrest the crooks. However, one thief slips out of the cottage and runs away with the money. Peter Sam blows his whistle loudly, surprising the thief who trips over. The Fat Controller makes sure that all the other engines are told about Peter Sam's heroism.
- The Fat Controller is initially said to arrive with a policeman, but there are actually two policemen.
- Peter Sam is illustrated with his old funnel, his footplate is grey, and his bufferbeam is drawn inaccurately.
- Peter Sam's bufferbeam is shorter than it should be in one illustration.
- Peter Sam has grey wheels.