It was common knowledge in Amsterdam that the famous café on the Staalstraat was his favorite haunt. And Rosner was hardly inconspicuous. Indeed, with his shock of white hair and rumpled tweed wardrobe, he was one of the most recognizable figures in Holland. The geniuses in the Dutch police had once suggested he utilize some crude disguise while in public, an idea Rosner had likened to putting a hat and a false mustache on a hippopotamus and calling it a Dutchman.

“I haven’t been to the Doelen in months.”

“That doesn’t mean it’s any safer.”

“I can’t live my life as a prisoner forever, Sophie.” He gestured toward the window. “Especially on a day like today. Wait until the last possible minute before you tell the reporter from De Telegraaf where I am. That will give me a jump on the jihadists.”

“That isn’t funny, Professor.” She could see there was no talking him out of it. She handed him his mobile phone. “At least take this so you can call me in an emergency.”

Rosner slipped the phone into his pocket and headed downstairs. In the entry hall he pulled on his coat and trademark silk scarf and stepped outside. To his left rose the spire of the Zuiderkirk; to his right, fifty yards along a narrow canal lined with small craft, stood a wooden double drawbridge. The Groenburgwal was a quiet street for the Old Side: no bars or cafés, only a single small hotel that never seemed to have more than a handful of guests. Directly opposite Rosner’s house was the street’s only eyesore, a modern tenement block with a lavender-and-lime pastel exterior. A trio of housepainters dressed in smudged white coveralls was squatting outside the building in a patch of sunlight.

Rosner glanced at the three faces, committing each to memory, before setting off in the direction of the drawbridge. When a sudden gust of wind stirred the bare tree limbs along the embankment, he paused for a moment to bind his scarf more tightly around his neck and watch a plump Vermeer cloud drift slowly overhead. It was then that he noticed one of the painters walking parallel to him along the opposite side of the canal. Short dark hair, a high flat forehead, a heavy brow over small eyes: Rosner, connoisseur of immigrant faces, judged him to be a Moroccan from the Rif Mountains. They arrived at the drawbridge simultaneously. Rosner paused again, this time to light a cigarette he did not want, and watched with relief as the man turned to the left. When he disappeared round the next corner, Rosner headed in the opposite direction toward the Doelen.