The mass that Berman had pulled out was confirmation. It had to have been a long-distance shot, toward the end of its trajectory. Had it been fired within a hundred yards, it would have penetrated Berman’s body and punched an exit wound. The amount of crumple and the size of the projectile: the crucial information was there.

He stooped and picked up the bullet. What had it been? A six- or seven-hundred-grain, brass-jacketed round. Penetration had been two inches; had it struck Berman’s head, it would have been instantly fatal. As it was, the lung hemorrhage made a fatal outcome fairly probable. What had it delivered: a hundred, two hundred foot-pounds of force?

Because of air resistance, impact diminished in a non-lineal relation to distance elapsed. The greater the velocity, the greater the air resistance, or drag force, so it wasn’t a simple, linear relation. The velocity-distance matrix involved a first-order differential equation, and Reynolds number—the sort of thing Alan Demarest could solve in his head, maybe Berman, too—but, relying on trained intuition, Janson estimated that the distance traversed would have been twelve hundred yards out, or about two-thirds of a mile.

Janson’s mind filled with the skyline of the area, the Palladian roofs of Hanover Terrace, the round dome of the Central London Mosque … and the minaret, the tall, slender tower with the small balcony, used by the muezzin to summon the faithful to prayer. Lacking intrinsic value, it was likely unguarded; a professional would have had no problem gaining entry. If Janson’s rough calculations were correct, one had.

It was diabolical. A sniper had stationed himself on the balcony of the minaret, a flyspeck from the perspective of Berthwick House, and bided his time, waiting in case his target appeared in the casement windows. He would have had plenty of time to figure out the requisite angles and trajectories. But how many men were even capable of such a shot? Were there forty such in the world? A couple of Russians. The Norwegian sniper who came in first in a worldwide competition hosted in Moscow last year. A couple of Israelis, with their Galil 7.62 rifles. A handful of Americans.

A master sniper had supernal skill, but he had supernal patience, too. He had to be responsive to uncertainties: in a long-range shot, even a slight unexpected breeze could push a flat shot several feet from its intended destination. A subject could move unexpectedly; in this case, Berman had raised his hand after the shot was fired. A sniper had to be aware of such possibilities. And he had to be more patient than his target.

And yet who was the target?

The butler had assumed it was his employer, Berman. A natural assumption. And a dangerous one. He recalled Berman’s arm around his shoulder, drawing him close. The bullet that hit the Russian was fifteen inches from Janson’s head.