n he went to the door
opposite leading into Cynthia's room. That door was also bolted, as I
had stated. However, he went to the length of unbolting it, and opening
and shutting it several times; this he did with the utmost precaution
against making any noise. Suddenly something in the bolt itself seemed
to rivet his attention. He examined it carefully, and then, nimbly
whipping out a pair of small forceps from his case, he drew out some
minute particle which he carefully sealed up in a tiny envelope.

On the chest of drawers there was a tray with a spirit lamp and a
small saucepan on it. A small quantity of a dark fluid remained in the
saucepan, and an empty cup and saucer that had been drunk out of stood
near it.

I wondered how I could have been so unobservant as to overlook this.
Here was a clue worth having. Poirot delicately dipped his finger into
liquid, and tasted it gingerly. He made a grimace.

"Coco--with--I think--rum in it."

He passed on to the debris on the floor, where the table by the bed had
been overturned. A reading-lamp, some books, matches, a bunch of keys,
and the crushed fragments of a coffee-cup lay scattered about.

"Ah, this is curious," said Poirot.

"I must confess that I see nothing particularly curious about it."

"You do not? Observe the lamp--the chimney is broken in two places; they
lie there as they fell. But see, the coffee-cup is absolutely smashed to
powder."

"Well," I said wearily, "I suppose some one must have stepped on it."

"Exactly," said Poirot, in an odd voice. "Some one stepped on it."

He rose from his knees, and walked slowly across to the mantelpiece,
where he stood abstractedly fingering the ornaments, and straightening
them--a trick of his when he was agitated.

"Mon ami," he said, turning to me, "somebody stepped on that cup,
grinding it to powder, and the reason they did so was either because it
contained strychnine or--which is far more serious--because it did not
contain strychnine!"

I made no reply. I was bewildered, but I knew that it was no good asking
him to explain. In a moment or two he roused himself, and went on with
his investigations. He picked up the bunch of keys from the floor, and
twirling them round in his fingers finally selected one, very bright
and shining, which he tried in the lock of the purple despatch-case. It
fitted, and he opened the box, but after a moment's hesitation, closed
and relocked it, and slipped the bunch of keys,