...and while tapping his finger on the table...
''Tell also Mr Spaulding that he is to encourage his employer to answer this advertisement... its of the outmost importance if we need this plan to succeed!''
''I am sorry Sir, can you please be a bit more specific?''
''Very well...'' the professor raised his hand...

''Mr Wilson is about to be proposed a job he cannot refuse. He is a pawnbroker and most of his work is conducted in the evenings. His assistant, our man, has proven very loyal by now and can handle anything that might come up in the pawn shop in the morinigs. Or so Mr Wilson believes. That is why Mr Wilson will accept a meaningless ovepayed morning job... but we'll make it look as if he was indeed selected amongs other candidates beacuse of his... red hair quality!''

''Mr Spaulding will be digging the tunnel in the mornings, while his employer will be working for us at another location. A small cost to be payed, 4 pounds a week actually, to Mr Wilson for our 30,000 gold napoleons...''
''Brilliant plan Sir!'' said the Colonel.