He felt like someone who has braked too suddenly and been hit in the wind. As he went out to his car he remembered that Tad Cullen would read that story in a few minutes’ time; if he had not read it already. He went back to the flat and was met in the lobby by a relieved Mrs Tinker.

‘Thank heaven you’re back. That American boy’s been on the phone and goin’ on somethink awful. I can’t make ’ead or tail of what ’e thinks he’s talkin’ about. Ravin’ mad, ’e is. I says: Mr Grant’ll ring you, I says, the minute ’e come in, but ’e can’t leave the phone alone. Just puts it down an’ picks it up again. I bin running backwards and forwards between the sink and the phone like a—’ The telephone rang. ‘There you are! There ’e is again!’

Grant picked up the receiver. It was indeed Tad, and he was all that Mrs Tinker had said. He was incoherent with rage.

‘But he lied!’ he kept saying. ‘That guy lied. Of course Bill told him all that!’

‘Yes, of course he did. Listen Tad…Listen…No, you can’t go and beat him to a jelly…Yes, of course you can find his house for yourself; I don’t doubt it, but… Listen, Tad!…I’ve been to his house…Oh, yes, even at this hour of the morning. I read my papers earlier than you do…No, I didn’t beat him up. I couldn’t…No, not because I’m windy but because he’s in Cumberland…Yes. Since Thursday…I don’t know. I’ll have to think about it. Give me until lunch-time. Do you trust my judgement on things in general?…Well, you’ll have to trust it in this. I must have time to think…To think up some evidence, of course…It’s customary…I’ll tell my story to the Yard, of course, and of course they will believe me. I mean, my story of Bill’s visit to Lloyd, and Lloyd’s lies to me. But proving that Charles Martin was Bill Kenrick is quite a different matter. Until lunch-time I shall be writing out a statement for the Yard. Come about one o’clock and we can have lunch together. In the afternoon I must turn the whole thing over to the authorities.’

He hated the thought. This was his own private fight. It had been his own private fight from the very beginning. From that moment when he had looked down through the open compartment door on to the dead face of an unknown boy. It was a thousand times more his private fight since his meeting with Lloyd.

He had begun to write, when he remembered that he had not yet picked up the papers he had left with Cartwright. He lifted the receiver, dialled the number, and asked for Cartwright’s extension. Could Cartwright possibly find a messenger to send round with those papers? He, Grant, was frantically busy. It was Saturday, and he was clearing up before going back to work on Monday. He would be very grateful.

He went back to his writing, and became so absorbed that he was conscious only in a dim way that Mrs Tinker had brought in the second post: the noon one. It was when he raised his glance from the paper to search his mind for a word, that his eye fell on the envelope she had laid beside him on the desk. It was a foolscap envelope, rather stiff and expensive, well-filled, and addressed in a thin, angular cramped hand that managed to be at once finicking and flamboyant.

Grant had never seen Heron Lloyd’s handwriting. He recognised it instantly.

He put down his pen; cautiously, as if the strange letter was a bomb and any undue vibration might send it off.