Premise: It's nothing much, but ”well, if you are going, will you tell him ” he dropped his voice to a whisper ”"I think I've found the extra coffee-cup!" I had almost forgotten that enigmatical message of Poirot's, but now my curiosity was aroused afresh.

Hypothesis: His voice was casual, but also careful and wary, when he told me that he had found the extra coffee cup.
Relation: entailment