Giraud glared, but continued:
“A man must have been connected with the case, in order to dig the grave. There is no man who actually benefits by the crime, but there was a man who thought he would benefit. I heard of Jack Renauld’s quarrel with his father, and of the threats that he had used. The motive was established. Now as to means. Jack Renauld was in Merlinville that night. He concealed the fact—which turned suspicion into certainty. Then we found a second victim—stabbed with the same dagger. We know when that dagger was stolen. Captain Hastings here can fix the time. Jack Renauld, arriving from Cherbourg, was the only person who could have taken it. I have accounted for all the other members of the household.”
Poirot interrupted:
“You are wrong. There is one other person who could have taken the dagger.”
“You refer to M. Stonor? He arrived at the front door, in an automobile which had brought him straight from Calais. Ah, believe me, I have looked into everything. M. Jack Renauld arrived by train. An hour elapsed between his arrival, and the moment he presented himself at the house. Without doubt, he saw Captain Hastings and his companion leave the shed, slipped in himself and took the dagger, stabbed his accomplice in the shed—”
“Who was already dead!”
Giraud shrugged his shoulders.
“Possibly he did not observe that. He may have judged him to be sleeping. Without doubt they had a rendezvous. In any case he knew this apparent second murder would greatly complicate the case. It did.”
“But it could not deceive M. Giraud,” murmured Poirot.
“You mock yourself at me. But I will give you one last irrefutable proof. Madame Renauld’s story was false—a fabrication from beginning to end. We believe Madame Renauld to have loved her husband—yet she lied to shield his murderer. For whom will a woman lie? Sometimes for herself, usually for the man she loves, always for her children. That is the last—the irrefutable proof. You cannot get round it.”