"You said a minute ago, Mr. Vance," argued Heath, "that Rex maybe suspected the old lady. Then why should he have accused Von Blon the way he did that day he had a fit?"
"The accusation primarily, I think, was a sort of instinctive effort to drive the idea of Mrs. Greene's guilt from his own mind. Then again, as Von Blon explained, Rex was frightened after you had questioned him about the revolver, and wanted to divert suspicion from himself."
"Get on with the story of Ada's plot, Vance." This time it was Markham who was impatient.
"The rest seems pretty obvious, don't y' know. It was unquestionably Ada who was listening at the library door the afternoon we were there. She realized we had found the books and galoshes; and she had to think fast. So, when we came out, she told us the dramatic yarn of having seen her mother walking, which was sheer moonshine. She had run across those books on paralysis, d' ye see, and they had suggested to her the possibility of focussing suspicion on Mrs. Greene—the chief object of her hate. It is probably true, as Von Blon said, that the two books do not deal with actual hysterical paralysis and somnambulism, but they no doubt contain references to these types of paralysis. I rather think Ada had intended all along to kill the old lady last and have it appear as the suicide of the murderer. But the proposed examination by Oppenheimer changed all that. She learned of the examination when she heard Von Blon apprise Mrs. Greene of it on his morning visit; and, having told us of that mythical midnight promenade, she couldn't delay matters any
