are occupied by one family, and indeed it is the exception that one family rents in its entirety so much as a floor.
In a basement room in one of those houses sat two men as unlike one another as it is possible to conceive. The room itself was strangely tidy and bare of anything but the necessary furniture. A camp bed was under the window in such a position as to give its occupant a view of the ankles of those people who trod the pavement of the little street.
A faded cretonne curtain hid an inner and probably a smaller room where the elder of the men slept. They sat on either side of a table, a kerosene lamp placed exactly in the centre supplying light for their various occupations.
The elder of the two was bent forward over a microscope, his big hands adjusting the focus screw. Presently he would break off his work of observation and jot down a few notes in crabbed German characters. His big head, his squat body, his long ungainly arms, his pale face with its little wisp of beard, would have been recognized by Oliva Cresswell, for this was Professor Heyler—"the Herr Professor," as Beale called him.
The man sitting opposite was cast in a different mould. He was tall, spare, almost æsthetic. The clean-shaven face, the well-moulded nose and chin hinted at a refinement which his shabby threadbare suit and his collarless shirt freakishly accentuated. Now and again he would raise his deep-set eyes from the book he was reading, survey the absorbed professor with a speculative glance and then return to his reading.
They had sat in silence for the greater part of an hour, when Beale's tap on the door brought the reader round with narrow eyes.
"Expecting a visitor, professor?" he asked in German.
"Nein, nein," rambled the old man, "who shall visit me? Ah yes"—he tapped his fat forefinger—"I remember, the Fraulein was to call."
He got up and, shuffling to the door, slipped back the bolt and turned it. His face fell when he saw Beale, and the man at the table rose.
