Markham sat for several minutes in a brown study.

    "As you say, Vance," he remarked without looking up, "the technique of the bolting of the door from the hall explains one phase of the problem, but I can't see that we're any further along toward a solution of the double murder. Brisbane, after all, was a victim. Why should he have been interested in bolting Archer in this room?"

    "Really, I couldn't say." Vance appeared as puzzled as Markham. "It might not have been Brisbane at all. The fact that the pins and the string were in his overcoat pocket means little . . . and yet . . ."

    "If you want my opinion," put in Heath, "it was that Chink. Chinamen are full of tricks. Look at the puzzles those yellow babies think up."

    At this moment the front door opened and slammed, and Burke called to the Sergeant from the lower hall. One of the detectives that had been sent out earlier that afternoon to check Miss Lake's and Grassi's alibis had returned to report. He was Emery, from the Homicide Bureau, who had worked on several other cases in which Vance had been interested.[23] He had been assigned to the Grassi alibi; and his report was brief and efficient.

    "I interviewed Doctor Montrose at the Metropolitan. This fellow Grassi arrived there a little after four, and then the two of 'em went to the doc's apartment in East 86th Street. Grassi stayed there for dinner and went out at eight, saying he had an appointment in Mount Vernon at nine. He asked the doc directions for getting to Grand Central station."

    Emery took out his note-book and opened it.

    "I then hopped out to the Crestview Country Club and talked to the steward. He was for being cagy, but he finally came through and dug up the head waiter and the porter. They both remembered the Italian—on account of Miss Lake, I guess—and as far as they recollected he didn't show up till late—round eleven. Miss Lake had a table reserved for the dance, but didn't get there till after Grassi did. The party broke up about twelve-thirty.—And that's all I got."

    Heath made a grimace at Markham.

    "That checks with his story. But what I wanta know is where he was between eight and eleven. And there's no way of finding out unless we get a freak break."

    "He was shuttling to and fro over our complicated transportation system—according to his tale," smiled Vance. Then he turned to Emery. "I say, did Doctor Montrose give you any titbits of gossip regarding Grassi's call aside from his request for information regarding Grand Central station?"

    "Nothing, sir." Emery shook his head with ponderous discouragement. "Except that the Italian was called up on the phone during dinner."

    When the detective had gone Vance went to the telephone and called Doctor Montrose at his home. After a few minutes' conversation he hung up the receiver and paced up and down.

    "That phone call to Grassi," he murmured, "—very strange. Doctor Montrose says it upset Grassi terribly. Hardly finished his dinner, and seemed in a hurry to get away. The phone was in the hall just outside the dining-room door and Montrose couldn't help hearing some of Grassi's end of the conversation. Montrose says he protested bitterly against the message he received—called it an outrage, and intimated strongly that he would take steps. . . . Steps—now what could that mean? And who could have called him and upset him? Who knew he was going to Montrose's for dinner? . . . It couldn't have been Miss Lake—he wouldn't have threatened her and then joined her at a country-club dance. And Wrede could have had no dealings with him. . . . Perhaps Brisbane . . . or Archer. . . ."

    It was growing dark and Vance switched on the electric lights. Then he sat down and inhaled deeply on his cigarette.

    "Archer—yes, it could have been. . . . Sergeant, suppose you fetch the signor."

    Heath went from the room, and Vance said to Markham:

    "Ceramics, I opine. Nothing would be so likely to stir up Grassi as a disappointment along that line. . . ."

    The Italian was ushered in by the Sergeant; and Vance went straight to the point.

    "Who telephoned to you, Mr. Grassi, at Doctor Montrose's yesterday during dinner?"

    Grassi gave a slight start; then looked defiantly at Vance.

    "It was a personal matter—my own affair."

    Vance sighed and with slow deliberation drew from his pocket the agreement that Archer Coe had written to Grassi regarding the sale of his collection. As Vance opened the letter and laid it on his knee, he watched Grassi. I, too, was watching the man, and I saw a peculiar change come over him. His eyes widened and stared; his face became almost blanched; and he stood with breathless rigidity as if suddenly transfixed by hypnosis.

    "It was Mr. Archer Coe who phoned you, was it not, Mr. Grassi?" came Vance's flat and unemotional voice.

    Grassi neither moved nor spoke.

    "Perhaps he regretted the bargain he had made with you for the sale of so many of his beloved pieces," Vance continued. "Perhaps he decided to call the deal off, after thinking it over alone with his treasures. . . . Perhaps he thought it best to inform you immediately of his decision so you would not talk of the transaction to Doctor Montrose. . . ."

    Still Grassi did not move, but the inevitable impression he gave was that Vance had guessed the import of the telephone call he had received at the Curator's home the night before.

    "I can well imagine how you felt, Mr. Grassi," Vance went on, without alteration of tone. "After all, the bargain had been made and you held Mr. Coe's letter of confirmation. But really, y' know, you shouldn't have threatened him—"

    Suddenly the Italian's pent-up emotion broke forth.

    "I had every right to threaten him!" he burst forth, the blood rushing back to his face. "For a week I have been negotiating—meeting his constantly increasing prices. Finally, yesterday, we reach an understanding. He puts it in writing, and I cable to Italy announcing my success. Then he rejects the agreement; he tells me he will not sell—that he has changed his mind. He insults me over the telephone: he says I have swindled him. He dares me to do anything about it! He even says to me that he will swear I forced him to sign that letter by pointing a revolver at him. . . ." Grassi raised his clenched hands in a gesture of outrage. "What could I do?" he almost shouted. "I threatened him as he had threatened me. I told him I would use any means at my disposal to hold him to his agreement. I was justified!"

    "Oh, doubtless—in such circumstances." Vance nodded vaguely. "What did Mr. Coe say then?"

    "What did he say?" Grassi took a step toward Vance and bent forward. He spoke in a curious, hushed tone. "He said he would break every vase he owned before he would let me have them."

    Vance gave a mirthless smile.

    "No wonder you were a bit disconcerted at the sight of those Ting yao fragments! . . . But Mr. Coe didn't smash the vase, Mr. Grassi. That desecration was achieved—inadvertently—by the person who killed him. Most unfortunate, what?"

    Vance got to his feet wearily, folded Archer Coe's letter, and held it out to Grassi.

    "If this document will comfort you, you may have it back. I believe I've finished with it. . . . That will be all for the present."

    Grassi hesitated. He studied Vance suspiciously for a moment. Then he took the letter, made a low bow, and left the room.

    Markham, who had been following the interview intently, addressed Vance as soon as Grassi was out of hearing.

    "A curious and ominous situation. Grassi is refused the collection, on which he has obviously set his heart and staked his honor; and he threatens Coe. Then he disappears for three hours, saying he took the wrong train; and this morning Coe is found dead, with all the superficial indications of suicide."

    "Exactly."

    "And what's more," added Heath aggressively, "Coe was stabbed in the back with a dagger. These Italians are mighty handy with the stiletto."

    "But why should he also stab Brisbane?" Vance asked dispiritedly. "And why the revolver? And why the bolted door? And especially why the Scottie? . . . We now have nearly all the parts of the puzzle, but none of them seems to fit."

    "You were counting a great deal on the dog this morning," Markham observed.

    "Yes, yes—the dog." Vance lapsed into silence for a while, his eyes gazing out of the east window into the gathering dusk of the October twilight. "And no one here liked dogs—no one but Wrede. Funny he should give his pet away. . . ." Vance's voice was scarcely audible: it was as though he were thinking out loud. "A Doberman Pinscher . . . too big, of course, to keep in a small apartment. And I wouldn't take Wrede for a dog lover. Too unsympathetic. . . . I think I'll have converse with him. . . ."

    He stepped to the telephone. A moment later he was talking with Wrede. The conversation was very brief, but during it Vance jotted down some notes on the phone pad. When he had replaced the receiver Markham gave an exasperated grunt.

    "Why should you be concerned with Wrede's former pets?" he asked.

    "I'm sure I don't know," Vance admitted frankly. "Some vague association perhaps. The unknown Scottie was found downstairs; and the only other dog that has been mentioned in this case is Wrede's. I'll confess the connection is far-fetched. But Wrede and dogs don't go together—the combination is almost as incongruous as was the presence of the wounded Scottie in the hall. And I hate incongruities."

    Markham strove to control his irritation.

    "Well, what did you learn about Wrede's dog?"

    "Nothing staggerin'. He had the Doberman only a few months—bought him at a show in Westchester. Then when he moved from his house in Greenwich Village to his present apartment he gave the dog to some friends of his." He pointed to the phone pad. "I have their name—they live on Central Park West, in the eighties. . . . I think I'll drop by and see them. Y' know, Markham, I'm dashed interested in Doberman Pinschers. They're beautiful dogs. And they were the original police dogs in Germany. 'Police dog' is a misnomer, however, when applied to any one breed. Almost any dog may be a police dog. We have the erroneous idea in this country that the German shepherd dog is the only police dog—in fact, he is called a Police Dog, as if the two names were synonymous. In England he is known as an Alsatian. The Doberman Pinscher is a cross between a shepherd dog and a Pinscher—the name given Continental terriers. He's a comparatively new breed, but has become very popular, for, aside from his beautiful conformation, he is strong, muscular, vigorous, intelligent, extremely alert, and, when incensed, vicious and savage. He's an excellent dog for police work, for, once fully trained, he retains his knowledge better than any other dog. . . ."

    Markham got up and yawned.

    "Thanks awfully. Your dissertation is most edifying. But I hardly think I'll call in a Doberman to solve the present case. It might make the Sergeant jealous."

    Heath grinned good-naturedly.

    "I'm for anything that'll solve this case, Chief. But I'm thinking that Mr. Vance may have something in his mind."

    "Sergeant," said Vance, going toward the door, "you flatter me abominably."

    It was decided to discontinue the investigation for the day. We were all tired and confused, and there were no leads to follow. The case was teeming with possibilities, but the contradictions of the various details made logical speculation well-nigh impossible. Vance suggested a complete cessation until he could make an inquiry into the ownership of the wounded Scottie. His sanguine attitude toward the presence of the dog in the house struck me as extravagant; and I knew Markham felt the same way about it. But since there was little more that could be done at the moment, he gave in hopefully to Vance's suggestions.

    "It's quite safe," Vance told him, when he had reached the lower hall, "to let the various members of the household go about their business. Only, they should be on hand tomorrow for interrogation. I can assure you, Markham, no one will run away."

    A short conference in the drawing-room settled the matter. Gamble was told to proceed with his duties, as usual; and Miss Lake and Grassi were informed that they were free to go and come as they chose, provided they were available for questioning.

    "Keep a man in Coe's bedroom, however," Vance admonished the Sergeant; "and it would also be well to have a man outside to check on any one entering or leaving the house."

    As we approached the front door Guilfoyle, the detective from the Homicide Bureau whom the Sergeant had sent to check Hilda Lake's alibi, came in and reported. But he had unearthed nothing helpful. Miss Lake had dined at Arrowhead Inn with friends, and had departed alone by motor, arriving at the Crestview Country Club about eleven o'clock. Guilfoyle had been unable to verify the motor accident which ostensibly had delayed her arrival at the Club.

    Vance, Markham and I went out into the chill air. It had been a day of horror, and the cool breeze from the park was invigorating. When we were entering the District Attorney's car, Markham asked: "Were you serious, Vance, about seeing those people to whom Wrede gave the Doberman Pinscher?"

    "Oh, quite. . . . It will take only a few minutes."

    The name of the people was Enright; and they lived in a penthouse in one of the new apartment buildings on Central Park West, almost opposite the reservoir. The butler informed us that Mrs. Enright was out of the city, and that Mr. Enright was at that moment walking the dog in the park. He suggested that we might find him on the circular path around the reservoir.

    Entering the park at 85th Street, we traversed the gardens on the west, crossed the main motor road, and cut across the lawn to the reservoir path. Few people were in the park at this hour and the figures about the reservoir were not many. We sat down on a bench by the path entrance and waited. Presently there appeared round the Fifth Avenue turn a very large man with a dog on a leash.

    "That will be Enright," said Vance. "Suppose we stroll toward him."

    Enright proved to be a genial, easy-going type of man of great bulk. (I learned later that he was an importer of food-stuffs from out-of-the-way places in the South Seas.) Vance introduced himself and presented Markham and me. Enright was cordial and talkative; and when Vance mentioned Wrede's name he became voluble regarding his long friendship with the man. As he chatted I had a good look at the dog. I was not familiar with the breed, but I was nevertheless struck with his qualities. He was lean and muscular, with beautiful lines, his coat a shiny black with rust-red, sharply defined markings. The dominating impression he gave was that of compact, muscular power, combined with great speed and intelligence—a dog that would make a loyal and protective friend and a dangerous enemy.

    "Oh, yes," Enright said, in answer to a question from Vance. "Wrede gave me and the missus Ruprecht last spring. Said he couldn't keep him in a small apartment. We've got a penthouse—plenty of roof for the fellow to run around. But I always take him out at night and give 'im a to-and-fro in the park. Good for him. Dogs get fed up with tiles and brickwork—need to feel the sod under their paws and to get their noses in the good earth now and then. Like human beings. I take a trip to the country every year—into the wilderness.—Rough it—get back to nature—"

    "Oh, quite," agreed Vance pleasantly. "But one does miss the conveniences when in the wilderness—doesn't one?"

    He went toward the Doberman and bent over, making a friendly clicking sound with his tongue and calling the dog gently by name. He extended the back of his hand slowly toward the dog's muzzle and ran his hand over his occiput and down his slightly arched neck. But the dog would not respond. He shrank back, gave a frightened whine, and crouched down on his haunches, trembling.

    "That don't mean he don't like you, Mr. Vance," Enright explained, patting the dog on the head. "He's shy as the devil. Distrustful of strangers. Gad! You should have seen him when I first got him. He crawled under a big settee in the den and wouldn't come out for two days—not even to eat. Had to drag him out twice a day and put him on the roof. Then back he'd go under the settee. . . . Queer ideas dogs get. Neither me nor the missus are formidable, and we love dogs. Wouldn't be without one. But Ruprecht is lots better now than he used to be. Getting a little confidence. He's pretty near all right when he's alone with me."

    "He'll probably get over it," Vance told him encouragingly. "The right treatment, don't y' know. . . . He's a beautiful specimen—not a Sieger Kanzler von Sigalsburg,[24] but he has a clean head, no lippiness, a long arched neck, a deep chest, muscular body and sloping back; and he's correct size—around seventy pounds, I'd say. . . . Ever show him?"

    "Oh, I entered him once—Cornwall. But he wouldn't show. Lay down in the ring and whimpered. Damn shame, too, for the two fellows that went over him lacked quality,—one had a loose shoulder, and the other was cow-hocked and had prominent light eyes."

    "It's all in the game," Vance murmured sympathetically.

    We walked with the garrulous Enright back to his apartment house and took leave of him. When we were in the District Attorney's car, headed down-town, Vance spoke, and his voice was troubled.

    "Something queer about that dog, Markham—something deuced queer. Why should he be timid? Why should he distrust and fear strangers? It's not like a Doberman to act that way. By nature they are alert and shrewd and fearless, with energetic natures. They're among the best watch dogs of all the larger breeds. . . . Shy—lying down in the ring. . . . Yes, something has happened to him. He's had a blighting experience of some kind. . . ."

    Markham beat an annoyed tattoo on the window ledge of the car.

    "Yes, yes; it's very sad, I suppose. But what possible connection can there be between a shy Doberman in Central Park West and the murder of Archer Coe?"

    "I haven't the vaguest notion," Vance returned cheerfully. "But there are only two dogs in this case, and one of them is browbeaten and timid, and the other is viciously wounded."

    "Pretty far-fetched," Markham grumbled.

    Vance sighed.

    "I dare say. But so are the circumstances surrounding the murders themselves." He lighted a fresh cigarette and glanced at his watch. "It's drawing on toward dinner time. Currie has promised me filet of sole Marguéry and Chatouillard potatoes, and hot-house strawberries Parisienne. Does that tempt you? . . . And I'll open a bottle of that '95 Château-Yquem you're so fond of."

    "You cheer me, old man." Markham gave an order to the chauffeur. "But first I'll take two double ponies of your Napoléon brandy. I'm in vile humor."

    "Ah, a bit of forgetfulness—eh, what? Quite right you are. There'll be nothing to irk us till tomorrow."

    But Vance was mistaken. That night the Coe case entered a new and more sinister phase. Markham dined with us and remained until nearly eleven chatting about various subjects from the drawings of George Grosz to Griffith Taylor's new theory of the migration and status of races. He departed with the understanding that he was to pick us up at ten the next day.

    It was exactly half-past two in the morning when Vance's private phone rang. It woke me from a deep sleep, and it was several minutes before I could answer it. Markham's voice came over the wire demanding Vance. I carried the portable phone set to his room and handed it to him in bed. He listened a brief minute; then he set the instrument on the floor, yawned, stretched, and threw back the bedclothes.

    "Dash it all, Van!" he complained, as he rang for Currie. "Grassi has been stabbed!"