Mrs. Hale.

"Are you sure your door was locked?"

"Certain. As soon as I missed the necklace I looked at the catch."

"That was in the morning. But the night before?"

"I always slip the spring. And I know I did this time because it had
been left unsprung so that Mr. Kirby's mother could come in and out of
my sitting-room, and I remember springing it when she left for bed."

"Sometimes these locks don't work." Slipping the catch back, Average
Jones pressed the lever down. There was a click, but the ward failed to
slip. At the second attempt the lock worked. But repeated trials proved
that more than half the time the door did not lock.

"So," observed Average Jones, "I think we may dismiss the key theory."

"But the locked door this morning?" cried Mrs. Hale.

"The intruder may have done that as he left."

"I don't see why," protested Kirby, in a tone which indicated a waning
faith in Jones.

"By way of confusing the trail. Possibly he hoped to suggest that he'd
escaped by the fire-escape. Presumably he was on the balcony when Mrs.
Hale came out into this room."

As he spoke Average Jones laid a hand on the heavy net curtains which
hung before the balcony window. Instead of parting them, however, he
stood with upturned eyes.

"Was that curtain torn before yesterday?" he asked Mrs. Hale.

"I hardly think so. The hotel people are very, careful in the up-keep of
the rooms."

Jones mounted a chair with scant respect for the upholstery, and
examined the damaged drapery. Descending, he tugged tentatively at the
other curtain, first with his right hand, then with his left; then
with both. The fabric gave a little at the last test. Jones disappeared
through the window.

When he returned, after five minutes, he held in his hand some scrapings
of the rusted iron which formed the balcony railing.

"You're a mining man, Mr. Kirby," he said. "Would you say that assayed
anything?"

Kirby examined the glinting particles. "Gold," he said decisively.

"Ah, then the necklace rubbed with some violence against the railing.
Now, Mrs. Hale, how long were you awake?"

"Ten or fifteen minutes. I remember that a continuous rattling of wagons
below kept up for a little while. And I heard one of the drivers call
out something about taking the air."

"Er--really!" Average Jones became suddenly absorbed in his seal ring.
He turned it around five accurate times and turned it back an equal
number of revolutions. "Did he--er--