Another Napolean of Crime?

    "I have come across him before," said Miss Silver " - not as Grey Mask of course; but in the last five or six years I have constantly come across small bits of evidence which have led me to suspect that there is one man behind a number of coordinated criminal enterprises. He pulls a great many strings, and every now and then I have come across one of them."

(from Grey Mask, by Patricia Wentworth)