Text: My idea was ”a very ridiculous one, no doubt ”that she had intended to poison him ”and that, in some way, Mrs. Inglethorp got hold of it by mistake.
Entailment: I wondered at first if she had intended to poison Mr. Inglethorp, but his wife was killed by mistake.
Contradiction: I always knew the truth from the beginning, that Mrs. Inglethorp was indeed the intended victim.