g to get in the house without waking the family, and when I came
back here to the front door, where I had left my valise, it was gone. I
thought you were the thief when you came out, and--we've lost all this
time. Somebody has followed me and robbed me!"

"What was in the bag?" I asked, stepping to the edge of the porch and
looking around, with the help of the candle.

"Valuable papers," he said shortly. He seemed to be dazed and at a loss
what to do next. We had both instinctively kept our voices low.

"You are certain you left it here?" I asked. The thing seemed incredible
in the quiet and peace of that neighborhood.

"Where you are standing."

Once more I began a desultory search, going down the steps and looking
among the cannas that bordered the porch. Something glistened beside the
step, and stooping down I discovered a small brown leather
traveling-bag, apparently quite new.

"Here it is," I said, not so gracious as I might have been; I had
suffered considerably for that traveling-bag. The sight of it restored
Wardrop's poise at once. His twitching features relaxed.

"By Jove, I'm glad to see it," he said. "I can't explain,
but--tremendous things were depending on that bag, Mr. Knox. I don't
know how to apologize to you; I must have nearly brained you."

"You did," I said grimly, and gave him the bag. The moment he took it I
knew there was something wrong; he hurried into the house and lighted
the library lamp. Then he opened the traveling-bag with shaking fingers.
It was empty!

He stood for a moment, staring incredulously into it. Then he hurled it
down on the table and turned on me, as I stood beside him.

"It's a trick!" he said furiously. "You've hidden it somewhere. This is
not my bag. You've substituted one just like it."

"Don't be a fool," I retorted. "How could I substitute an empty satchel
for yours when up to fifteen minutes ago I had never seen you or your
grip either? Use a little common sense. Some place to-night you have put
down that bag, and some clever thief has substituted a similar one. It's
an old trick."

He dropped into a chair and buried his face in his hands.

"It's impossible," he said after a pause, while he seemed to be going
over, minute by minute, the events of the night. "I was followed, as
far as that goes, in Plattsburg. Two men watched me from the minute
I got there, on Tuesday; I changed my hotel, and for all of
yesterday--Wednesday, that is--I felt secure enough