"We must do what we can to break off your father's friendship with this
woman," I declared. "It is distinctly dangerous for him."
"Yes, Mr Kemball," she cried. "I only wish we could! I only wish--"
Her sentence was interrupted by a sound which startled both of us. We
listened, looking into each other's serious face without uttering a
word. The sound emanated from the next room--Shaw's bedroom--the door
of which was closed.
It was that low, peculiar whistle which I had first heard on the morning
I had visited Titmarsh after poor Guy's mysterious death, and had heard
on a second occasion when visiting at Lydford.
"There's Dad again?" she cried, in a strained voice. "He evidently
doesn't know we are still up." The whistle was again repeated--a low,
long-drawn, peculiar sound, in a high shrill note.
It was not the unconscious whistle of a man thinking, but a sound full
of meaning--a distinct call, which even as we listened in silence was
repeated a third time.