He shudders fastidiously as the last of five pages of single-spaced description hisses out of the ink-jet printer. It joins the half dozen contact pages of photographs, including his fiber-optic examination of the interior of the instrument, and an invoice for just over two thousand pounds. He shakes the bundle of pages together, and binds them neatly with a paper clip from a desk drawer. Then they go inside the envelope the woman who called herself Cassie May gave him. He licks the flap and seals it, then, in a moment of curiosity, he switches on the anti-counterfeit lamp he keeps by the cash register and examines it under ultraviolet light. Nothing shows up: it bears none of the UV-fluorescent dots the Post Office prints on envelopes to control their routing.

If "Cassie May" thinks she can retrieve an unmarked envelope from the postal system she's welcome to it, in Mr. Dower's books. He turns back to the computer and deletes his work, then sighs and glances at the clock. Five minutes to closing time: no point keeping the shop open any longer. He stands and stretches, switches the computer off, and goes through an abbreviated version of his regular closing routine; no point banking the cash register contents (his takings before the woman's visit barely amounted to petty cash). He pulls on his coat, turns his coffee mug upside down on the draining board, switches off the lights, and opens the front door.

The woman is waiting for him. She smiles. "Have you finished your report?" she asks.

Mr. Dower nods, confused. "I was going to post it, as you requested." He pats his coat pocket.

"I'm in a hurry. There's a rush on. If you don't mind . . . ?" She looks at him impatiently.

"Of course." He pulls out the envelope and hands it to her. "My invoice is enclosed."

"You don't need to worry about that side of things." She slides the envelope into her black patent leather handbag and smiles.

"I suppose not. You people always pay your debts eventually."

"Yes, you can be absolutely certain of that."

He turns back to the door and fumbles with his key ring. Which is why he doesn't see her withdraw a silenced pistol from her bag, raise it to the back of his head, and discharge a single round into his cerebellum. The gun makes little sound—just the racking click of its action—but as she fires, the suppressor fitted to its muzzle frosts over with clear fluid, air in contact with it liquefying as it chills to just above absolute zero. Mr. Dower slumps forward against the door. The woman's arm follows him down with absolute precision and discharges a second round into the top of his skull, but it is unnecessary: he is already dead.