And the handkerchief yielded nothing—­not even when inspected under the drop-light and with the aid of a microscope.  Not a mark to indicate who carried it nor whence it came.—­Yet stay; in the closed room he detected what had been lost in the open:  a faint, a very faint, odour as of azurea sachet.  It was only a suggestion; vague and uncertain, and entirely absent at times.  And Harleston shook his head.  The very fact that there was nothing about it by which it might be identified indicated the deliberate purpose to avoid identification.  He put it aside, and, taking up the roses, laid them under the light.

They were the usual American Beauties; only larger and more gorgeous than the general run—­which might be taken as an indication of the wealth of the giver, or of the male desire to please the female; or of both.  Of course, there was the possibility that the roses were of the woman’s own buying; but women rarely waste their own money on American Beauties—­and Harleston knew it.  A minute examination convinced him that they had been crushed while being worn and then trampled on.  The stems, some of the green leaves, and the edges of one of the blooms were scarred as by a heel; the rest of the blooms were crushed but not scarred.  Which indicated violence—­first gentle, then somewhat drastic.

He put the flowers aside and picked up the envelope, looked it over carefully, then, with a peculiarly thin and very sharp knife, he cut the sealing of the flap so neatly that it could be resealed and no one suspect it had been opened.  As he turned back the flap, a small unmounted photograph fell out and lay face upward on the table.

Harleston gave a low whistle of surprise.

It was Madeline Spencer.

II

THE VOICE ON THE WIRE

“Good morning, madame!” said Harleston, bowing to the photograph.  “This is quite a surprise.  You’re taken very recently, and you’re worth looking at for divers aesthetic reasons—­none of which, however, is the reason for your being in the envelope.”

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.”