Specter's Gamble

Desmond started walking across the street when he tripped on the metal grid that covered the rain duct. His arm shot forward and he grabbed onto the smoking man's wrist, to keep himself from falling. The playboy was caught completely by surprise and dropped his cigarette.
"What the hell?!" he yelled out when he almost lost his balance as well.
Desmond quickly drew back his hand, twisting the ring on his finger.
"Sorry, man!" he said and raised both palms up in a 'Please-forgive-clumsy-me' gesture.
"Watch where the hell you are going!" the man snapped irritably.
"Sorry," Desmond said again and walked away, blending into the crowd almost instantly.

He knew that the guy never even noticed a weak prick on his wrist, and even if he did, he would forget all about it in a couple of minutes. An hour or so later, he'll be writhing in pain so horrible that he won't remember his own name, let alone some clumsy idiot who bumped into him on the sidewalk. He'd be dead by midnight, just as Desmond's contractor wanted. He would go through two or three hours of agony at the most, but Desmond knew for sure that those hours would seem like eternity to him.
He made his way to the phone booth and dropped several coins into the slot. He didn't have to look for the phone number - it was imprinted in his memory. Desmond never had any problems with remembering things - numbers, words, addresses, you name it. He had to look at something only once, and it would be stored in his memory forever. He considered it a gift.
"Done," he said shortly into the receiver after he heard a 'click' on the other end of the line. "Finish the transfer."