"That's for us to ascertain."
"And how are we going to do it?"
"By means of the man he hired as a substitute," declared Britz in positive tone.
"But how—how?" demanded Manning.
"That will depend on circumstances. Now I'm ready to hear the developments at this end."
Manning settled back in his chair with the relieved air of one about to discard an irksome burden. From a drawer of his desk he produced half a dozen long envelopes which he tossed to Britz.
"They contain all the reports of the men," said he. "You'd better go through them at your leisure to-night or to-morrow morning. It's useless to discuss the case further until you've familiarized yourself with them."
As they left Headquarters for their homes, the three men realized that despite the many developments of the case, they had, as yet, barely penetrated the surface. Every new discovery had only succeeded in adding further complications to the mystery. The evidence thus far was fragmentary, disconnected, throwing an uncertain light on the crime. The substitution of prisoners tended to involve Beard, yet it gave not the least hint of the motive that actuated the killing of Whitmore. Nor did it reveal how the crime was committed. That it would prove of importance, of vital significance in solving the crime, Britz believed implicitly. But, such are the complexities in all human things, that the possibility of error is never eliminated. And in a criminal investigation a single error may destroy every chance of success, just as a single error on the part of the criminal may destroy all the safeguards which he has so carefully thrown around him.
At the Seventy-second street station of the subway Britz bade his companions good night. Dismissing the Whitmore case and all other police business from his mind, he headed straight for his home, retired at once and fell into a deep sleep.