When he entered his mother's room, and saw her obviously poisoned, he jumped to the conclusion that Mademoiselle Cynthia knew something about the matter. 
There were no signs she was poisoned.
mnli hypothesis: There were no signs she was poisoned. premise: When he entered his mother's room, and saw her obviously poisoned, he jumped to the conclusion that Mademoiselle Cynthia knew something about the matter. 