On the way to the Castle he was so mysterious with Robert Black that the stout constable became a prey to mingled curiosity and doubt. He could not make up his mind whether William Roper really knew something of importance or was merely vapouring. William Roper neither gratified his curiosity, nor banished his doubt. He was alive to the advantage of reserving his information for the most important ear, so as to gain the greatest possible credit for it.
At the first sight of him Mr. Flexen felt that he had before him an important witness, for he took a violent dislike to him, and he had observed, in the course of his many years' experience in the detection of crime, that the most important witness in hounding down a criminal was very often of a repulsive type, the nark type. William Roper was of that type, but his story was indeed startling.
He first told how he had seen Colonel Grey kiss Lady Loudwater in the afternoon—Mr. Flexen noted that Lord Loudwater had accused her of kissing Grey—and of their spending most of the afternoon in the pavilion in the East wood. The time of his watching had already lengthened in William Roper's memory. There was nothing new in these facts, and Mr. Flexen saw no reason to suppose that they had any bearing on the crime. But William Roper went on to say that soon after ten in the evening he had been on his round in the East wood, when he saw Colonel Grey walking in the direction of the Castle. His curiosity had been aroused by what he had seen in the afternoon, and thinking it not unlikely that he was on his way to another meeting with the Lady Loudwater, and that it was the duty of a faithful retainer to make sure about it, with a view to informing his master should his surmise prove correct, he followed him.
The Colonel went straight through the wood into the Castle garden, walked round the Castle, keeping in its shadow as he went, till he stood under the window of Lady Loudwater's suite of rooms.
There he appeared to suffer a check. There was a light in the room on the ground floor under her boudoir. The Colonel had waited quite a while; then he had walked round the Castle and into it by the library window.
William, greatly surprised by the Colonel's audacity, had taken up his position in a clump of tall rhododendrons, opposite the library window, from which he could keep watch on it.
"What time would this be?" said Mr. Flexen.
"It couldn't have been more than twenty minutes past ten, sir," said
William Roper.
"And what happened then?" said Mr. Flexen.
"Nothing 'appened for a good ten minutes. Then James Hutchings, the butler, come across the gardens from the south gate, as if 'e'd come from the village, and 'e went in through the libery winder—the same winder."