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suspect any one," McAdams replied. "Because there are only two persons who could have had any possible information as to how to open the box and the police are obliged to admit that neither of these could have taken the emerald."
The detective's interlocutor smiled appreciatively and slapped his hand lightly on the table.
"Among the persons implicated in this affair," he said impressively, "there must necessarily be some one for whom that admission of innocence need not be made. The necessity is to locate that person. My own interest in the matter, of course you understand, is purely mental. My name is Du Brock—my friend's name Lund. I am one of those people who cannot bear to see a matter which offers an intricate and fasci-
