In the face of these awkward alternatives, Merrington pursued the quest for Nepcote with vigour. The men working immediately under his instructions were spurred into an excess of energy which brought about the detention of several young men who could not adequately explain themselves or their right to liberty in the great city of London. But none of these captures turned out to be Nepcote. Merrington believed he was hiding in London, but at the end of five days he still remained mysteriously at liberty in spite of the constant search for him. He seemed to have disappeared as completely as though he had passed out of the world and merged his identity into a chiselled name and a banal aspiration on a tombstone.

In the angry consciousness of failure, Merrington was not blind to the fact that he had only his own impetuosity to blame for allowing Nepcote to slip through his fingers. His mistake was due to his dislike of private detectives and his unbelief in modern deductive methods of crime solution. His own system, which is the system of Scotland Yard, was based on motive and knowledge. If he found a strong motive for a crime he searched for the person to whom it pointed. If there was no apparent motive he fell back on his great knowledge of the underworld and its denizens to fit a criminal to the crime. The system has its measure of success, as the records of Scotland Yard attest.

Merrington had brought both methods to bear in his handling of the Heredith case. When his original investigations failed to reveal a motive for the murder, he determined to return to London to ascertain what dangerous criminals were at liberty who might have committed the murder. His own view then was that the murder was the work of an old hand who had entered the moat-house to commit burglary, and had murdered Mrs. Heredith to escape identification. The isolation of the moat-house, the presence of guests with valuable jewels, the time chosen for the crime, and the scream of the victim, tended to confirm him in this belief. Caldew's chance discovery about Hazel Rath, and the subsequent events which arrayed such strong circumstantial evidence against her, brought the other side of the system uppermost and set Merrington seeking for a motive which would accord with the presumption of the girl's guilt. Having found that motive, he was satisfied that he had done his duty, and he thought very little more about the case.

It was his tenacious adhesion to conservative methods which caused him to blunder in his treatment of Colwyn's information about the missing necklace. He rarely acted on impulse. His habitual distrust of humanity was deep, and to it was wedded a wariness which was the heritage of long experience. But his obstinate conviction of Hazel Rath's guilt led him to make a false move in his effort to square the loss of the necklace with the evidence against the girl. His own poor opinion of human nature hindered him from seeing, as Colwyn had seen, any inconsequence between such widely different motives as maddened love and theft; that was one of those subtle differentiations of human psychology in which his coarse-grained temperament was at fault. It is probable that Merrington's dislike of private detectives contributed to obscure his judgment at a critical moment. He was unable to see that Colwyn, by reason of his intellect and practical capacity, stood in a class apart and alone.

In his contemplation of the case Merrington's thoughts turned to Colwyn, and he wondered in what direction the private detective's investigations into the case had progressed—if they had progressed at all—since he had seen him last. In a chastened mood, he reflected that Colwyn had not only given him a warning which was annoyingly different from other advice in being well worth following, but had acted generously in informing him of the missing necklace when he might have kept the discovery to himself, in order to score a point over Scotland Yard and place one of the Yard's most distinguished officials in an awkward position.

With a belated but unconscious recognition of an intelligence which far surpassed his own, Merrington felt that it would be worth while to have another talk with Colwyn, in the hope of finding some way out of the perplexities in which he had plunged himself by permitting Nepcote to escape.

The next interview, which was of his seeking, took place at Colwyn's rooms in the evening, after Merrington had previously arranged for it by telephone. The face of the private detective revealed neither surprise nor resentment at the sight of Merrington. He invited his guest to sit down, and then seated himself a little distance from the table, on which whisky and cigars were set out.

"Well, Mr. Colwyn, you were right and I was wrong about that fellow Nepcote," Merrington commenced, realizing that it was best to come to the point at once. "I wish now that I had followed your advice."

"If you hadn't gone to see him perhaps you wouldn't know as much as you know now," said Colwyn drily.

"That's one way of looking at it," responded Merrington with his great laugh. "Unfortunately, that interview caused Nepcote to bolt, and so far he has shown us a clean pair of heels."