The desks were bright yellow but, in places, the polish had worn off and the bare wood showed. There were little partitions for different papers – ‘For Attention’ – ‘For Review’ – ‘Mail In’. Suddenly he stopped reading the black, stencilled letters, for his own desk was empty; everything had been removed since he had been there that morning.

He turned away, taking his hand out of his pocket and drawing the envelope with it. He looked down at the crumpled paper, frowning. It was thick and newish-looking; had it been in his pocket for some time it would have been grubby. He remembered thinking that morning that it was a fortnight since he had last worn his raincoat. He had not noticed the envelope then.

It was sealed and there was no writing on it. He inserted a finger at one end and ripped it open. Inside was a single slip of paper on which were two or three lines of block letter writing, upside down. He turned it swiftly and read :

Dear West,

I’ve another proposition I think will interest you. It will pay even better than the last. Meet me at the usual place, tomorrow, Wednesday, at 7.30, will you?K.

At first startled, then tight-lipped, Roger re-read it. All that it meant and all it might have led to passed through his mind, together with a fact which he had to face and which almost stupefied him. ‘Another proposition’, inferring that there had been plenty of others; ‘It will pay even better’ . . .’ meet me at the usual place . . .’

A film of sweat broke out on his forehead.

To Abbott it would be just the evidence he wanted — and he had brought it into the Yard himself! He might easily have left his coat on a peg and gone to try to see Chatworth, which was his chief reason for coming. He stared down, studying the ‘K’ more closely; it was a carefully-formed letter; the whole note had been written by someone who knew how to use a pen. It was in drawing-ink, jet black and vivid against the white paper.