It was a Scrano! A blaze of orange and yellow triangles, the canvas was painted in the Italian artist's smooth, slick style, and yet it had a feeling of depth that made Qwilleran reach out to touch the surface. Down in the comer was the famous signature, daubed in block letters.

Qwilleran set it aside and turned another painting around to face the room. Again, triangles! These were green on blue. Behind this canvas there were more — gray on brown, brown on black, white on cream. Proportions and arrangements varied, but the triangles were all pure Scrano.

A throaty murmur from Koko attracted Qwilleran's attention. The cat was sniffing the orange triangles on the yellow background. Qwilleran wondered what it was worth. Ten thousand? Twenty thousand? Perhaps even more, now that Scrano would paint no more.

Had Mountclemens been cornering the market? Or were these forgeties? And in either case… who was stealing them?

Koko's nose covered the surface of the painting in great detail, as if he were experiencing the texture of the canvas, visible under the pigment. When he came to the signature, his neck was stretched, and he tilted his head first to one side and then to the other, as he strained to get close to the letters.

His nose moved from right to left, first tracing the 0, then studying the N, moving on to the A, sniffing the R with gusto as if it were something special, then on to the C, and finally lingering over the S.

"Remarkable!" said Qwilleran. "Remarkable!"

He hardly heard the turning of a key in the back door, but Koko heard it. The cat vanished. Qwilleran froze as the door slowly opened.

The figure that stood in the doorway made no move. In the half light Qwilleran saw square shoulders, heavy sweater, square jaw, high square brow.

"Narx!" said Qwilleran.

The man came to life. He sidled into the room, reaching for the table. His eyes were on Qwilleran. With a lunge he seized the palette knife and rushed forward.

Suddenly… shrieks… snarls! The room was full of flying things — swooping down, across, back, up, and over!

The man ducked. The hurtling bodies were quicker than the eye. They screamed like harpies. They flew down, under, up, across. Something hit him in the arm. He faltered.

In that half moment Qwilleran pounced on the flash, light and swung it with all his force.

Narx staggered back, went down. There was a sharp, rending crack as his head struck the tiled counter. He slumped slowly to the floor.

It was five,thirty at the Press Club, and Qwilleran was relating the story for the hundredth time. All day Monday the personnel of the Daily Fluxion had been filing past his desk to hear the details firsthand.

At the Press Club bar Odd Bunsen said, "I wish I'd been there with my camera. I can picture our hero phoning the police with one hand and holding up his pants with the other."

"Well, I had to tie Narx with my belt," Qwilleran explained. "When his head hit the tile counter, he was out cold, but I was afraid he'd come around while I was phoning the police. I'd already tied his wrists with my neck, tie — my good Scotch tie — and the only thing I had for his ankles was my belt."

"How did you know it was Narx?"

"When I saw that square face and those square shoulders, I thought of those pictures of robots, and I knew this man must be the artist. Painters, I've been told, always put some quality of themselves on canvas — whether they paint kids or cats or sailboats. But Koko was the one who made it all clear when he read Scrano's signature back, wards."

Arch said, "How does it feel to be playing Dr. Watson to a cat?"

Odd said, "What about the signature? That's something I missed?"

"Koko read the signature on this painting," Qwilleran explained, "and he spelled it out backwards. He always reads backwards."

"Oh, naturally. It's an old Siamese custom."

"That's when I realized that Scrano, the painter of the triangles, was also O. Narx, the painter of the robots. Their painted surfaces had the same slick metallic effect. A few minutes later the robot himself walked into the house and came at me with a palette knife. He would have got me, too, if Koko hadn't come to the rescue."

"Sounds as if that cat's in line for a Civilian Citation. What did he do?"

"He went berserk! And one Siamese flying around in a panic looks and sounds like a pack of wildcats. Zoom — screech — wham! I thought there were six animals in that room, and that fellow Narx was one bewildered guy."

"So Scrano is a fake," said Arch. "Yep. There's no Italian recluse hiding out in the Umbrian Hills," said Qwilleran. "There's only Oscar Narx manufacturing triangle pictures for Mountclemens to plug in his column and sell in his art gallery."

"Funny why he wouldn't use his own name," said Odd.

Then Arch said, "But Mountclemens' last column said there wouldn't be any more stuff from Scrano."

"I think Mountclemens was planning to eliminate Oscar Narx," said Qwilleran. "Maybe Narx knew too much. I suspect our critic was not on that three o'clock plane the day of Lambreth's murder. I suspect he had an accomplice who used the plane ticket and entered Mountclemens' name on the passenger list. And I'll bet that accomplice was Narx."

"And then Mountclemens took a later flight," said Arch.

"Or drove to New York," said Qwilleran, "in the mysterious station wagon that was parked behind the gallery in the late afternoon. Zoe Lambreth heard her husband talking about it on the phone."

Odd Bunsen said, "Mountclemens was crazy to let an, other guy in on the plot. If you're going to commit murder, go it alone, I always say."

"Mountclemens wasn't stupid," said Qwilleran. "He probably had a clever alibi figured out, but something went wrong."

Arch, who had been hearing fragments of Qwilleran's story all day, said, "What makes you so sure Mountclemens was going to kill somebody when he went down to his backyard?"

"Three reasons." Qwilleran was enjoying himself. He was speaking with authority and making large gestures. "First, Mountclemens went down to the patio to meet someone, and yet this vain man left his prosthetic hand upstairs. He wasn't going to greet a guest, so he didn't need it. Second, he did not take the flashlight, although the steps were icy and treacherous. Third, I suspect he took a kitchen knife instead; there's one missing."

Qwilleran's audience was hanging on every word.

"Apparently," he went on, "Mountclemens failed to take Narx by surprise. Unless he could surprise him and sink the knife in his back as Narx came through the gate, there was a good chance that the younger man would overpower the critic. Narx is a powerful, looking adversary, and it was one hand against two."

"How do you know Mountclemens went downstairs to meet someone?"

"He had on his lounging coat. He probably had his topcoat over his shoulders while waiting for Narx, then threw it off to get ready for action. Narx would unlock the gate, which swings into the patio, and Mountclemens would be waiting behind it, ready to knife him in the back. He probably planned to deposit the body in the alley, where the murder would be blamed on a tramp. It's that kind of neighborhood."

"If Narx is as formidable as you say," said Arch, "how did that fool think he could pull off the job with one hand?"

"Vanity. Everything Mountclemens did, he did superbly. It gave him an impossible conceit And I think I know why he failed this time. It's only a guess, but here's how I figure it: When Narx was unlocking that patio gate, he was alerted to Mountclemens' presence."

"How?"

"He smelled that lime-peel scent that Mountclemens always wore."

"Cr-r-razy!" said Odd Bunsen.

Arch said, "Narx might have gotten away with murder if he hadn't come back for those paintings."