Lawrence would say no more, so I decided that I would descend from my high horse, and once more seek out Poirot at Leastways Cottage. 
Lawrence would say no more because he was hiding something.
mnli hypothesis: Lawrence would say no more because he was hiding something. premise: Lawrence would say no more, so I decided that I would descend from my high horse, and once more seek out Poirot at Leastways Cottage. 