TWELVE! rang out the final stroke from the clock-tower. A low, eerie
whistle, minor, rising in three irregular notes and falling in weird,
unusual cadence to silence again, came from somewhere outside the room.

Then darkness--stillness--with the moon a witness of one more ghastly
crime.

Presently, confused and intermingled voices from above proclaimed the
return of Leroux with the doctor. They were talking in an excited
key, the voice of Leroux, especially, sounding almost hysterical. They
created such a disturbance that they attracted the attention of Mr. John
Exel, M. P., occupant of the flat below, who at that very moment had
returned from the House and was about to insert the key in the lock of
his door. He looked up the stairway, but, all being in darkness, was
unable to detect anything. Therefore he called out:--

"Is that you, Leroux? Is anything the matter?"

"Matter, Exel!" cried Leroux; "there's a devil of a business! For
mercy's sake, come up!"

His curiosity greatly excited, Mr. Exel mounted the stairs, entering
the lobby of Leroux's flat immediately behind the owner and Dr.
Cumberly--who, like Leroux, was arrayed in a dressing-gown; for he had
been in bed when summoned by his friend.

"You are all in the dark, here," muttered Dr. Cumberly, fumbling for the
switch.