So far Wogan’s speculations had travelled when the moonlight streamed out beneath his door too.  It made now a silver line across the passage broken at the middle by the wall between the rooms.  The mat had been removed, the candle put out, the prying was at an end; in another moment the door would surely open.  Now Wogan, however anxious to discover who it was that spied, was yet more anxious that the spy should not discover that the spying was detected.  He himself knew, and so was armed; he did not wish to arm his enemies with a like knowledge.  There was no corner in the passage to conceal him; there was no other door behind which he could slip.  When the spy came out, Wogan would inevitably be discovered.  He made up his mind on the instant.  He crept back quickly and silently out of the mouth of the passage, then he made a noise with his feet, turned again into the passage, and walked loudly towards his door.  Even so he was only just in time.  Had he waited a moment longer, he would have been detected.  For even as he turned the corner there was already a vertical line of silver on the passage wall; the door had been already opened.  But as his footsteps sounded on the boards, that line disappeared.

He walked slowly, giving his spy time to replace the letter, time to hide.  He purposely carried no candle, he reached his door and opened it.  The room to all seeming was empty.  Wogan crossed to a table, looking neither to the right nor the left, above all not looking towards the bed hangings.  He found the letter upon the table just as he had left it.  It could convey no knowledge of his mission, he was sure.  It had not even the appearance of a letter in cipher; it might have been a mere expression of Christmas good wishes from one friend to another.  But to make his certainty more sure, and at the same time to show that he had no suspicion anyone was hiding in the room, he carried the letter over to the window, and at once he was aware of the spy’s hiding-place.  It was not the bed hangings, but close at his side the heavy window curtain bulged.  The spy was at his very elbow; he had but to lift his arm—­and of a sudden the letter slipped from his hand to the floor.  He did not drop it on purpose, he was fairly surprised; for looking down to read the letter he had seen protruding from the curtain a jewelled shoe buckle, and the foot which the buckle adorned seemed too small and slender for a man’s.

Wogan had an opportunity to make certain.  He knelt down and picked up the letter; the foot was a woman’s.  As he rose up again, the curtain ever so slightly stirred.  Wogan pretended to have remarked nothing; he stood easily by the window with his eyes upon his letter and his mind busy with guessing what woman his spy might be.  And he remained on purpose for some while in this attitude, designing it as a punishment.  So long as he stood by the window that unknown woman cheek by jowl with him must hold her breath, must never stir, must silently endure an agony of fear at each movement that he made.