"I see," said the Chief Inspector. "So we must assume, if we are to assume anything at all, that Rockingham somehow succeeded in leaving his bedroom upon the nights in question."
"Yes," said Protheroe. "That was my idea. Higgins is prepared to swear that he locked Mr. Rockingham into his room on those two nights as on every other night."
"What sort of man is Higgins?"
"Seems thoroughly reliable," replied Inspector Protheroe. "But I have not yet been able to check his h'antecedents."
"Thank you, Protheroe," said Wilkins. "This information may very possibly be of value, and I am sure you will agree that, pending further inquiries, Rockingham should be watched. Perhaps you would arrange for a man to be posted in the grounds. Can you spare a couple of men to take on the job turn and turn a
