But perhaps one of Mrs. Inglethorp's keys would open it." He tried several, twisting and turning them with a practiced hand, and finally uttering an ejaculation of satisfaction. 
None of the keys would open it. 
mnli hypothesis: None of the keys would open it.  premise: But perhaps one of Mrs. Inglethorp's keys would open it." He tried several, twisting and turning them with a practiced hand, and finally uttering an ejaculation of satisfaction. 