Underneath the study windows there was only the narrowest ledge of rock between that side of the house and the edge of the cliffs.

A descent from the windows with a rope was hazardously possible, but ascent and entrance by that means was out of the question.
On the other hand, the theory of interior inaccessibility had a flaw in it, due to the presence of five different people in the room before the police arrived.

Their actions and motives would have to be most carefully weighed and sifted before the implication of the discovery of the finger-marks could be determined.
The rather breathless entrance of Inspector Dawfield put an end to Barrant's reflections.

He explained that Sergeant Pengowan, in his anxiety to maintain the correctness of his official report, had taken him to various breakneck positions at the back of the house and along the cliffs in order to demonstrate the impossibility of anybody entering Robert Turold's rooms from outside.

The sergeant was at that moment engaged in a room downstairs drawing up his reasons for that belief.