He drew out the sheet of paper and opened it. On it were typewritten,
without address nor signature, these letters:

DPNFNZQFEFBPOYVOAEELEHHEJYD
BIWFTCCFVDXNQYCECLUGSUGDZYJ
ENRYUIGYBSNRTDUHJWHGYZIPEPA
WPPOIMCHEIPRFBJXFVWWFTZNJPY
UFJDILDCEMBRVZDAYVAWALUMOFN
FCVDPGLPWFUUWVIEPTKVIPUMSFZ
NPSJJRFYASGZSDACSIGYUOFCEXA
AOIDJJFCJPSONPKUUYVCVCTIHDP
XMNOYKENHUSKHYMSFRRPCYWSLLW
SMVPPUNEIFIDJLZRWEHPQGODFUZ
TCEMQIQWNFYJTAALUMHJXILEEHY
ISOVOAZUCUDINBRLUZICUOTTUSV
LPNFFVQFANPVCYJHILTPFISGHCW
HYICPPNFDOUOCLDUWEIVIPJNQBV
ZLMIJRVKDSFRLWEGBKQYWSFFBEI
YORHMYSHTECPUTMPJXFNRNEEUME
ILJBWV.

"Cipher!" commented Harleston, looking at it with half-closed eyes....
"The Blocked-Out Square, I imagine. No earthly use in trying to dig it
out without the key-word; and the key-word--" he gave a shrug. "I'll let
Carpenter try his hand on it; it's too much for me."

He knew from experience the futility of attempting the solution of a
cipher by any but an expert; and even with an expert it was rarely
successful.