説明
"A big engineering concern is time and again outbidden by a rival organisation in tendering for contracts. There is obviously a leakage of information from the Board Room, and even when the strictest watch is being kept on all the staff who are engaged in the estimating department and they are practically kept prisoners, the leakage still continues. Who could be responsible, and how is the information being smuggled out? Let Harry Stephen Keeler tell you."