To whom had the dead man signalled in the Morse code by raising and lowering the blind?
Someone, friend or enemy, had been waiting outside near Clarence Gate in Regent’s Park in the expectation of a message.
He received it from the Professor’s own hands, those hands which before the dawn were cramped in the stiffness of death.
Chapter Four.
A Silent Message.
For a full hour we remained there in the presence of the dead.
Before that huddled figure I stood a dozen times trying to form some feasible theory as to what had actually occurred within that room.
The problem, however, was quite inexplicable. Who had killed Professor Greer?