"Just what--if anything--is this supposed to mean, sir?" he demanded in an unsteady voice. Barney hesitated aware that Fredericks had remained in the hall just beyond the study. But Fredericks obviously was in McAllen's confidence. His eavesdropping could do no harm. "It means this, doctor--" Barney began, amiably enough; and he proceeded to tell McAllen precisely what the photographs meant. McAllen broke in protestingly two or three times, then let Barney conclude his account of the steps he had taken to verify his farfetched hunch on the pier without further comment. After a few minutes Barney heard Fredericks' steps moving away, and then a door closing softly somewhere, and he shifted his position a trifle so that his right side was now toward the hall door. The little revolver was in the right-hand coat pocket. Even then Barney had no real concern that McAllen or Fredericks would attempt to resort to violence, but when people are acutely disturbed--and McAllen at least was--almost anything can happen. * * * * * When Barney finished, McAllen stared down at the photographs again, shook his head, and looked over at Barney. [Illustration] "If you don't mind," he said, blinking behind his glasses, "I should like to think about this for a minute or two." "Of course, doctor," Barney said politely. McAllen settled back in the chair, removed his glasses and half closed his eyes. Barney let his gaze rove. The furnishings of the house were what he had expected--well-tended, old, declining here and there to the downright shabby. The only reasonably new piece in the study was a radio-phonograph. The walls of the study and of the section of a living room he could see through a small archway were lined with crammed bookshelves. At the far end of the living room was a curious collection of clocks in various types and sizes, mainly antiques, but also some odd metallic pieces with modernistic faces. Vacancies in the rows indicated Fredericks might have begun to dispose discreetly of the more valuable items on his employer's behalf. McAllen cleared his throat finally, opened his eyes, and settled the spectacles back on his nose. "Mr. Chard," he inquired, "have you had scientific training?" "No." "Then," said McAllen, "the question remains of what your interest in the matter is. Perhaps you'd like to explain just why you put yourself to such considerable expense to intrude on my personal affairs--" Barney hesitated perceptibly. "Doctor," he said, "there is something tantalizing about an enigma. I'm fortunate in having the financial means to gratify my curiosity when it's excited to the extent it was here." McAllen nodded. "I can understand curiosity. Was that your only motive?" Barney gave him his most disarming grin. "Frankly no. I've mentioned I'm a businessman--" "Ah!" McAllen said, frowning.