“What is it now?” she asked.

“I require the metal object, approximately two pounds in weight, that I left at your gallery yesterday afternoon.”

“The Beretta nine-millimeter?”

“Yes, that’s the one.”

“It’s resting on my bedside table.”

“Mind if I drop by and collect it?”

“Since when do you ask before making entry into my abode?”

“It’s the new me.”

“I was quite fond of the old you.”

Gabriel’s train arrived at half past eight. He traveled by Tube from King’s Cross to Gloucester Road, then made the short walk to Sarah’s maisonette in Queen’s Gate Terrace. She was drinking coffee at the kitchen island, dressed in stretch jeans and a Harvard pullover. Her blond hair was wound into an untidy top knot. The condition of her blue eyes was indicative of a late night.

“I foolishly agreed to have dinner with Julian and Oliver,” she explained while massaging her right temple.

“Why?”

“Because it was a Friday, and I didn’t want to spend it searching for something to watch on Netflix.”

“Where’s your husband?”

“Vanished to parts unknown. Haven’t heard from him in days.” She looked down at the Beretta, which was lying on the countertop. “Most men bring a girl flowers. But not Gabriel Allon.”

He slipped the gun into the waistband of his trousers at the small of his back.

“Feel better?”

“Much.”

Sarah yawned elaborately, then asked, “How was Paris?”

“Quite interesting. But if I had known about your dinner plans, I would have taken you with me.”

“You brought me something expensive, I hope.”

Gabriel placed the iPhone on the countertop.

“Since you don’t use an Apple device, I’ll assume that isn’t yours.”

“It belonged to a Parisian physician named Emanuel Cohen.”

“Belonged?”

“Dr. Cohen fell down the steps of the rue Chappe in Montmartre two nights ago. The French police believe it was an accident, which wasn’t the case.”

“Says who?”

“Amadou Kamara. He sells counterfeit handbags on the streets of Paris for Papa Diallo. Amadou saw someone push Dr. Cohen down the steps.”

“How did you get his phone?”

“I bought it from Papa Diallo. He made a special price for me. A thousand euros. That was in addition to the five hundred I gave Amadou for two fake handbags.”

“How shrewd of you.” Sarah drank some of her coffee. “I’m sure there’s a perfectly reasonable explanation for all this.”

“Untitled portrait of a woman in the surrealist style, oil on canvas, ninety-four by sixty-six centimeters.”

“Picasso?”

Gabriel nodded.

“There are several untitled portraits, if memory serves.”

“That’s correct. And one of them belonged to Cohen’s grandfather, a man named Bernard Lévy. He foolishly entrusted it to his lawyer during the Occupation.”

“And the lawyer undoubtedly sold it.”

“But of course.”

“Should I assume that Dr. Cohen was looking for this painting at the time of his death?”

“Actually, he was convinced he’d found it.”

“Where?”

“An art gallery in the Geneva Freeport. He asked the world’s leading expert on the wartime French art market, a woman named Naomi Wallach, to prove that it was his grandfather’s Picasso.”

“Isn’t Naomi Wallach working for the Louvre now?”

“Which is why she told Cohen she couldn’t take the case. She did, however, suggest an alternative.”

“Not Charlotte Blake?”

Gabriel nodded.

“But she was murdered by the Chopper.”

“She was murdered with a hatchet,” said Gabriel. “Whether it was wielded by the Chopper is unclear. In fact, there are inconsistencies with the previous killings.”

“Do you think she was murdered because of the Picasso?”

“I do now.”