A collection of four stories chronicling the adventures of several railway engines. The Fat Controller ordered one goods engine from Scotland and was surprised and disturbed to receive two, called Donald and Douglas. Unfortunately they had lost their numbers and they were identical twins. You can imagine the confusion they caused, for no one could tell which was which. 15.1 Hullo Twins! 15.2 The Missing Coach 15.3 Break Van 15.4 The Deputation