Alleyn moved to the tall windows … They looked out over the charming little garden to the Chelsea reaches of the Thames.

‘A few hours ago’—he repeated her words slowly—‘the river was breathing mist. The air was threaded with mist and as cold as the grave. That was before dawn broke. It was beginning to get light when I saw him. And look at it now. Not a cloud. The damned river’s positively sparkling in the sunlight. Come here, Troy.’

She stood beside him.

‘Look down there into the street. Through the side window. At half-past three this morning the river mist lay like a pall along Cheyne Walk. If anybody was awake at that mongrel hour or abroad in the deserted streets they would have heard a taxi come along Cheyne Walk and stop outside this gate. If anybody in this house had had the curiosity to look out of one of the top windows they would have seen the door of the taxi open and a quaint figure in a cloak and wide-brimmed hat get out.’

‘What do you mean? He got out?’

‘The watcher would have seen this figure wave a gloved hand and heard him call to the driver in a shrill voice: ‘Sixty-three Jobbers Row, Queens Gate.’ He would have seen the taxi drive away into the mist—and then—what? What did the figure do? Did it run like a grotesque with flapping cloak towards the river to be swallowed up in vapour? Or did it walk off sedately into Chelsea? Did it wait for a moment, staring after the taxi? Did Bunchy’s murderer pull off his cloak, fold it and walk away with it over his arm? Did he hide his own tall hat under the cloak before he got out of the taxi, and afterwards change back into it? And where are Bunchy’s cloak and hat, Troy? Where are they?’

‘What did the taxi-driver say?’ asked Troy. ‘There’s nothing coherent in the papers. I don’t understand.’

‘I’ll tell you. Fox will be here soon. Before he comes I can allow myself a few minutes to unload my mind, if you’ll let me. I’ve done that before—once—haven’t I?’

‘Yes,’ murmured Troy. ‘Once.’

‘There is nobody in the world who can listen as you can. I wish I had something better to tell you. Well, here it is. The taxi-driver brought Bunchy to the Yard at four o’clock this morning, saying he was murdered. This was his story. He picked Bunchy up at three-thirty some two hundred yards from the doors of Marsdon House. There was a shortage of taxis and we suppose Bunchy had walked so far, hoping to pick one up in a side street, when this fellow came along. The unnatural mist that hung over London last night was thick in Belgrave Square. As the taximan drove towards Bunchy he saw another figure in an overcoat and top-hat loom through the mist and stand beside him. They appeared to speak together. Bunchy held up his stick. The cabby knew him by sight and addressed him: