Collis saw the door of Sarah’s carriage open, and Sarah herself begin to step down. He saw Martin turn in his seat and wave to the Chilean driver to wait.

‘I don’t wait!’ screamed the Chilean. ‘I stop, and I don’t never get moving no more! You shift your ass! You move!’

Martin said something in reply which Collis couldn’t hear. But the Chilean shook his head fiercely and cracked his whip again, so that his huge disastrous load continued to bear down on the Melford’s brougham at the same relentless pace. Collis was sitting rigidly in his chair his fists clenched in apprehension. Now, for God’s sake. Now!

With the orchestrated timing of one of those elaborate clockwork toys, everything happened at once. Dan McReady rushed forward from the alley, in his blue doorman’s jacket and his bushy false whiskers, and took Sarah’s hand as if he were claiming first prize in a raffle. Nodding and bowing, he busily assisted her to step down on to the wooden sidewalk, and at the same time jostled his large green Winn’s umbrella around so that Martin found it impossible to see his face.

Dan smartly slammed the carriage door, whistled a piercing whistle between his teeth, and shouted, ‘Off you go now, driver!’

Martin hesitated, but the Chilean was screaming at him again, ‘Move out! Move out!’ and so he tipped his hat to Sarah, released his handbrake, and drove the Melford carriage away. Collis caught a momentary glimpse of Sarah standing on the sidewalk under Dan’s umbrella, modestly but elegantly dressed in a grey overcoat, and he could see that she was smiling at the chaos in the street. But then a Chinese laundryman passed in front of Winn’s window, with a bundle of washing on his head, and when Collis looked again she was gone.

That was all. He didn’t even hear the cab in the alley pull away. He could hardly believe it was over, and he sat back on his wroughtiron chair feeling peculiarly deflated. What was worse, he would have to wait here for at least ten minutes more, to make sure that his alibi was conclusive. He called the waiter and ordered another cup of coffee.

‘Is that clock correct?’ he asked. ‘My visitor was supposed to be here by three.’

‘The correctest clock in the city, sir,’ the waiter said sarcastically.

Collis drank more coffee, and the minutes passed by so slowly that he felt as if he’d been sitting in Winn’s all day. At last, at twenty past three, the waiter came across and flicked his tablecloth with a napkin. ‘It seems as if your lady friend has been unavoidably detained, doesn’t it, sir?’ he said.

Collis glared at him. ‘Yes,’ he snapped, with as much self-control as he could muster.

‘I don’t mean to offend, sir,’ said the waiter.

Collis tossed two bits on to the table. ‘I know you don’t mean to,’ he said. ‘The trouble is that you do.’