ded himself with another padlock of precisely
the same make and size, has substituted _that_, locked it with its
proper key and so left it!"

"What! Then that was why----"

"That, of course, was why you supposed it to be out of order when you
attempted to open it with _your_ key. As a matter of fact, it is even
now in perfectly good order, except for the damage we have jointly
committed with the screw-driver. And now, observe! That lock was shut by
another key; if the man that did that is as sharp as I suppose he is, he
will have got rid of that key at once. But perhaps he hasn't; and if
not, then the man who has that key is the thief. At any rate, the key is
the clue we must hunt for. Let us have your clerks in one by one, and
look at their keys. Some are out at lunch by this time, probably?"

"No--I said they might be wanted, so kept them. I thought you might
prefer to see them before they went out."

"Very well thought of, but perhaps scarcely judicious, on the whole.
Because if there _is_ a guilty person among them it may give him a
hint; and the odds are rather against its being very useful, considering
the possibility--even probability--that the bonds and the collateral
evidence left here days ago. But we'll look at their keys, by all means,
and then they may go to lunch as soon as you please. Let me do the
talking, or perhaps you'll start a scare. Send for the nearest clerks
first, then the others. As each comes in, mention his name, so that I
can hear it. Say, 'Oh, Mr. Brown'--or Jones, or what not--'have you some
keys about you?' Don't mention my name, and I will do the rest. Push to
the door of the safe, and lock this drawer in the table."

Mr. Bell did as Hewitt directed, and then called the head clerk, Mr.
Foster, from his room, with the prescribed inquiry about keys.

"Yes, Mr. Foster," Hewitt added pleasantly, "I'm not sure that the lock
is quite in order, but I promised to open it for Mr. Bell, so we'll
try."

Mr. Foster, a slim, active old gentleman, grown grey in the firm's
service, pulled a bunch of keys from his pocket, and Hewitt scrutinised
each narrowly. "No," he said, "I'm afraid none of these will do. Stay,"
he added suddenly, and turning his back, carried the bunch to the
window. "No," he concluded, as he came back to the table and tried one
of the keys fruitlessly. "No, I'm afraid none of those will do. Thank
you, Mr. Foster. You don't happen to have any more, do you?"

No, Mr. Foster