he door can't be locked," Morriston said, pushing it.

The footman rose and pushed too, but the door showed no sign of yielding;
it was fastened sure enough.

"This is strange," Morriston said. "Hi! Is any one in there?" he
shouted; but no response came.

"Are you sure the key is in the door on the inside?" he asked.

"Certain, sir. Will you look for yourself, sir?" the man replied,
striking another match and holding it so that his master could
convince himself.

"No doubt about that," Morriston declared, as he rose from his scrutiny.
"It is the most extraordinary thing I have ever known. Can you account
for it, Stent?"

The butler shook his head. "No, sir. Unless someone is in there now."

Morriston again shouted, but no answer came.

"I presume there is no way out of the room but this door," Piercy asked.

"None," Morriston answered; "except the window, and that is, I should
say, quite eighty feet from the ground; eh, Mr. Gifford?"

"A sheer drop of quite that distance," he answered.

"A prohibitive mode of exit," Piercy observed with a smile.

"Yes," Morriston said. "I can't understand it at all. Besides, who would
be likely to want to play tricks here? We have had no sign of burglars,
and in any case they would hardly have been able to bring a ladder long
enough to reach up to that window. Well, we must have the mystery cleared
up. I think, Stent, you had better send one of the men on a bicycle into
Branchester to fetch a locksmith and have the door opened somehow. Have
it explained to him that it may be a tough job. In the meantime we may as
well go and view the tower from the outside, as we can't get in."

Accordingly the whole party went down into the hall and so out to the
garden, where they strolled round the house, Piercy meanwhile taking
notes of its architectural features. As they came to the tower the rays
of a late winter sun were striking it almost horizontally, lighting it up
in a picturesque glow. Piercy, with his archaeological knowledge, was
able to tell the owner and Gifford a good deal about the ancient
structure of which they had previously been ignorant.

"The sunset would have been worth seeing from that top window,"
Morriston said, evidently perplexed and annoyed over the mystery of the
locked door. "I can't make out what has happened."

"The person who locked the door assuredly did not make his exit by the
window," Kelson remarked with a laugh, as he looked up at the sheer
surf