“Abe didn’t twig at first! Didn’t catch on, he swears he didn’t, but a week later, I caught him chortling at something in the Times. The bloke he’d run to earth had fallen off the top deck of a number fifty-two bus. The bit at the back. The fall alone might not have killed him, but the bus following on a few yards behind certainly did. Nasty! I couldn’t think why Abe was laughing. Ironic? Two days later, a messenger arrived at the office with a small parcel. When I opened it, out popped twenty lovely, brand-new five-pound notes and a typed note with them: Many thanks for discreet services rendered, it said.”

“A hundred quid? Bloo . . . Well, I never!” said MacFarlane in astonishment. He kept Edith fixed with his dark, double-barrelled stare, his fingers were leading a life of their own, scribbling a short note to himself. “Have you a date for what we might call this ‘first contract’?”

“Um . . . In 1919. It was the week before my birthday. So it would have been coming up to the seventh of April.” She fingered a row of pearls at her throat. “Abe peeled off one of the fivers and told me to get myself something nice.”

MacFarlane’s fingers registered another thought.

Her expression hardened. “Thinking you’re in the wrong job, Sunshine? You could be right. There’s a vacancy now. Interested? That’s when it all started up. The phone calls! ‘A friend of mine assures me that—in complete confidentiality, of course—proof of the undertaking will, naturally, be required.’”

“Proof?” MacFarlane leapt to his feet in his agitation. “What sort of proof did they expect of cold-blooded murder? A foreskin, a right ear, a head on a plate?”

“Nothing of the sort, Superintendent! Abe was never less than civilised. And by this time he was a dab hand with a pocket Kodak. He’d been involved with lots of domestic cases . . . you know, marital.” Edith’s chin went up defiantly. “The arrangement was that cash came in, half on requisition and the other half on completion. When the job was done, Abe would take a shot of the corpse—always identifiable and in a recognisable situation chosen by the client—as proof and put it in the post. They could never be traced back to him because he did all his own developing. He held on to the negatives in case he ever had trouble with a client not playing the game.”

Trying for a calm he didn’t feel, MacFarlane asked, “And does he still have these gems on file somewhere?”

“Yes. You’re bound to find them when you raid the premises, so I’ll earn a Brownie point and tell you—red metal file cabinet, northeast corner of the stockroom next to the bottom drawer. The key’s on Abe’s keyring. Did you find it?”