“I—­beg your pardon,” he apologized as he began to unlock the handcuffs.

“Here, my man, what are you doing?” interrupted Balcom.

“I know my business.  You lay off,” growled the detective.

A moment later Locke, with a slight smile on his handsome face, was answering the telephone.

Not a soul save the detective, even yet, suspected the true identity of Locke, even as he answered over the telephone with a respectful, “Yes, sir.”

The fact of the matter was that the message had come most opportunely.  It was from the chief of the Department of Justice himself, ordering Locke to stay at the house until he had secured the evidence that would allow the department to proceed against the company under the anti-trust law.  That, then, was the explanation of the secret dictagraph which Locke had installed, the explanation of his apparent faithlessness to his employer.

But weightier matters were now on Locke’s mind.  Here he was faced by the case of his life, involving the happiness of the very girl whom he had so soon come to love.  His incentive was double—­love and success:  triple—­above all, justice.

By this time the household themselves were sufficiently calm to help Brent to his bedroom and Flint to a guest-chamber.

Balcom was about to follow, when Locke, returning from the telephone, touched him on the shoulder and shoved the threat message which Brent had given him the night before under the face of the junior partner.

“Read that,” he demanded.

Balcom read, controlling his features admirably, if control were necessary.

“What’s the meaning of this?” he demanded, coldly.

“Were you in Madagascar lately?” shot back Locke.

Locke could not be sure whether or not Balcom suppressed a start.  At any rate, he did not conceal anger at the insinuation.

“Certainly,” he replied.  “With my son I cruised through the Mozambique Channel and touched at Madagascar last summer.  Why?”

Locke nodded and the detective made a note of the reply.

“What do you mean to insinuate by that question?” demanded Balcom.

Without reply Locke shrugged nonchalantly and smiled.

Not ten feet away, in the conservatory door, Paul listened, and his face darkened as he clenched his fists.

There was a murderous glare in Paul’s eyes as Locke unconcernedly withdrew, whispering to the detective, who nodded deferentially to the young scientist who had been assigned by the Department of Justice, strangely, to the very case which now he realized in some unknown way must concern himself and the very mystery of his own identity.

So wore along the morning, with growing mystery and excitement.

It was not long before the Brent family physician was summoned, and after a careful diagnosis pronounced Brent in a hopeless state as far as his own science was concerned.  Eva was by this time more than frantic.  The consolation of Paul seemed to add to her nervousness.  She was almost distracted when she heard Balcom and the doctor discussing the case in low tones in her father’s room.