He had been in the night club only about ten minutes, but during those ten minutes fully a dozen people had more or less hurriedly departed.  Because of the arrangements already made by Sergeant Coombes, the addresses of many of these departing visitors would be in Kerry’s possession ere the night was much older.  And why should they have fled, incontinent, if not for the reason that they feared to become involved in the Kazmah affair?  All the cabmen had been warned, and those fugitives who had private cars would be followed.

It was a curious scene which Kerry surveyed, a scene to have interested philosopher and politician alike.  For here were representatives of every stratum of society, although some of those standing for the lower strata were suitably disguised.  The peerage was well represented, so was Judah; there were women entitled to wear coronets dancing with men entitled to wear the broad arrow, and men whose forefathers had signed Magna Charta dancing with chorus girls from the revues and musical comedies.

Waiting until the dance was fully in progress, Inspector Kerry walked slowly around the room in the direction of the stair.  Parties seated at tables were treated each to an intolerant stare, alcoves were inspected, and more than one waiter meeting the gaze of the steely eyes, felt a prickling of conscience and recalled past peccadilloes.

Bill had claimed Mollie Gretna for the dance, but: 

“No, Bill,” she had replied, watching Kerry as if enthralled; “I don’t want to dance.  I am watching Chief Inspector Kerry.”

“That’s evident,” complained the young man.  “Perhaps you would like to spend the rest of the night in Bow Street?”

“Oh,” whispered Mollie, “I should love it!  I have never been arrested, but if ever I am I hope it will be by Chief Inspector Kerry.  I am positive he would haul me away in handcuffs!”

When Kerry came to the foot of the stairs, Mollie quite deliberately got in his way, murmured an apology, and gave him a sidelong gaze through lowered lashes, which was more eloquent than any thesis.  He smiled with fierce geniality, looked her up and down, and proceeded to mount the stairs, with never a backward glance.

His genius for criminal investigation possessed definite limitations.  He could not perhaps have been expected in tactics so completely opposed to those which he had anticipated to recognize the presence of a valuable witness.  Student of human nature though undoubtedly he was, he had not solved the mystery of that outstanding exception which seems to be involved in every rule.

Thus, a fellow with a low forehead and a weakly receding chin, Kerry classified as a dullard, a witling, unaware that if the brow were but low enough and the chin virtually absent altogether he might stand in the presence of a second Daniel.  Physiognomy is a subtle science, and the exceptions to its rules are often of a sensational character.  In the same way Kerry looked for evasion, and, where possible, flight, on the part of one possessing a guilty conscience.  Mollie Gretna was a phenomenal exception to a rule otherwise sound.  And even one familiar with criminal psychology might be forgiven for failing to detect guilt in a woman anxious to make the acquaintance of a prominent member of the Criminal Investigation Department.