Another taxi took us to the address Flossie Monro had given us, a squalid block of Mansions in an unsavoury neighbourhood. It was some time before we could gain admission to Miss Monro's flat, but we had at least the satisfaction of knowing that no one could leave it whilst we were on guard outside.
Eventually we got in. It was plain that some one had been before us. The contents of drawers and cupboards were strewn all over the floor. Locks had been forced, and small tables had even been overthrown, so violent had been the searcher's haste.
Poirot began to hunt through the débris. Suddenly he stood erect with a cry, holding out something. It was an old fashioned photograph frame—empty.
He turned it slowly over. Affixed to the back was a small round label—a price label.
"It cost four shillings," I commented.
"Mon Dieu! Hastings, use your eyes. That is a new clean label. It was stuck there by the man who took out the photograph, the man who was here before us, but knew that we should come, and so left this for us—Claud Darrell—alias Number Four!"
15. THE TERRIBLE CATASTROPHE
It was after the tragic death of Miss Flossie Monro that I began to be aware of a change in Poirot. Up to now, his invincible confidence in himself had stood the test. But it seemed as though, at last, the long strain was beginning to tell. His manner was grave and brooding, and his nerves were on edge. In these days he was as jumpy as a cat. He avoided all discussion of the Big Four as far as possible, and seemed to throw himself into his ordinary work with almost his old ardour. Nevertheless, I knew that he was secretly active in the big matter. Extraordinary-looking Slavs were constantly calling to see him, and though he vouchsafed no explanation as to these mysterious activities, I realised that he was building some new defence or weapon of opposition with the help of these somewhat repulsive-looking foreigners. Once, purely by chance, I happened to see the entries in his pass-book—he had asked me to verify some small item—and I noticed the paying out of a huge sum—a huge sum even for Poirot who was coining money nowadays—to some Russian with apparently every letter of the alphabet in his name.
But he gave no clue as to the line on which he proposed to operate. Only over and over again he gave utterance to one phrase. "It is the greatest mistake to underestimate your adversary. Remember that, mon ami." And I realised that that was the pitfall he was striving at all costs to avoid.
So matters went on until the end of March, and then one morning Poirot made a remark which startled me considerably.