As she was about to depart Poirot detained her.
"One moment; have you ever seen among the effects of Mr. Opalsen a card like this?"
He held out a plain white card, rather highly glazed and uncommon in appearance. The maid took it and scrutinized it carefully.
"No, sir, I can't say I have. But, anyway, the valet has most to do with the gentlemen's rooms."
"I see. Thank you."
Poirot took back the card. The woman departed. Poirot appeared to reflect a little. Then he gave a short, sharp nod of the head.
"Ring the bell, I pray of you, Hastings. Three times, for the valet."
I obeyed, devoured with curiosity. Meanwhile Poirot had emptied the waste-paper-basket on the floor, and was swiftly going through its contents.
In a few moments the valet answered the bell. To him Poirot put the same question, and handed him the card to examine. But the response was the same. The valet had never seen a card of that particular quality among Mr. Opalsen's belongings. Poirot thanked him, and he with-
