"Of course, the head may be buried in the wood," said Zena.
Quarles looked at me inquiringly.
"I searched the wood with that idea in my mind," I said. "One or two doubtful places I had dug up. I think the murderer must have taken the head with him."
"To bury somewhere else?" asked Quarles.
"Perhaps not," I answered.
"A mad doctor bent on brain experiments—is that your theory, Wigan?"
"Not necessarily a doctor, but some homicidal maniac who is also responsible for the Normandy murder. The likeness between the two crimes can hardly be a coincidence."
"What was the date of the French murder?"
"January the seventeenth."
"Nearly the same date as the English one," said Zena.