They climbed the stairs, Gabriel at Isherwood’s shoulder, quiet as a bodyguard. His leather coat did not rustle, his jeans did not whistle, his brogues seemed to float over the carpet. Isherwood had to brush against Gabriel’s shoulder to remind himself he was still there. At the top of the stairs a security guard asked Gabriel to open his leather shoulder bag. He unzipped the flap and showed him the contents: a Binomag visor, an ultraviolet lamp, an infrascope, and a powerful halogen flashlight. The guard, satisfied, waved them forward.

They entered the salesroom. Hanging from the walls and mounted on baize-covered pedestals were a hundred paintings, each bathed in carefully focused light. Scattered amid the works were roving bands of dealers—jackals, thought Isherwood, picking over the bones for a tasty morsel. Some had their faces pressed to the paintings, others preferred the long view. Opinions were being formed. Money was on the table. Calculators were producing estimates of potential profit. It was the unseemly side of the art world, the side Isherwood loved. Gabriel seemed oblivious. He moved like a man accustomed to the chaos of the souk. Isherwood did not have to remind Gabriel to keep a low profile. It came naturally to him.

Jeremy Crabbe, the tweedy director of Bonhams’ Old Master department, was waiting near a French school landscape, an unlit pipe wedged between his yellowed incisors. He shook Isherwood’s hand joylessly and looked at the younger man in leather at his side. “Mario Delvecchio,” Gabriel said, and as always, Isherwood was astonished by the pitch-perfect Venetian accent.

“Ahhh,” breathed Crabbe. “The mysterious Signore Delvecchio. Know you by reputation, of course, but we’ve never actually met.” Crabbe shot Isherwood a conspiratorial glance. “Something up your sleeve, Julian? Something you’re not telling me?”

“He cleans for me, Jeremy. It pays to have him look before I leap.”

“This way,” Crabbe said skeptically, and led them into a small, windowless chamber just off the main saleroom floor. The exigencies of the operation had required Isherwood to express a modicum of interest in other works—otherwise Crabbe might be tempted to let it slip to one of the others that Isherwood had his eye on a particular piece. Most of the pieces were mediocre—a lackluster Madonna and child by Andrea del Sarto, a still life by Carlo Magini, a Forge of Vulcan by Paolo Pagani—but in the far corner, propped against the wall, was a large canvas without a frame. Isherwood noticed that Gabriel’s well-trained eye was immediately drawn to it. He also noticed that Gabriel, the consummate professional, immediately looked the other way.

He started with the others first and spent precisely two minutes on each canvas. His face was a mask, betraying neither enthusiasm nor displeasure. Crabbe gave up trying to read his intentions and passed the time chewing his pipe stem instead.