`I swear I didn't! But I didn't know, and I was afraid to tell when he explained it to me…!’
'I'll tell you what you did, Marks,' said Dr Fell, forgetting all about the Ghost and threatening in a natural voice. `Sir William gave me all the facts. You're a good valet, Marks, but you're one of the stupidest creatures in God's` world. Sir William bought two new hats on Saturday. One of the opera-hats he tried on at the shop was too large for him. But a mistake was made, and they sent the large one to him along with the Homburg, which was of the right size. Ha? You saw it. You wear the same size. But Sir William was going out to the theatre that night. You know what sort of a temper he has. If he found a hat that slid down over his forehead, he'd make it hot for the first person he could lay hands on….’
`Naturally you wanted his hat to be the right size, didn't you, Marks? But there wasn't time to get another hat; it was Saturday evening. So you did the natural thing. You used the same quick makeshift people have been using since hats were invented. You neatly stuffed the band on the inside with paper, the first harmless-looking paper you could find….'
Hadley flung the tin revolver on the table. `Good God, he said, `do you seriously mean to tell us that Marks tightened up the fit of that hat with Sir William's manuscript?'
`Sir William,' the doctor said, amiably, `gave us two clues himself which were absolutely, revealing. He said that the manuscript consisted of thin sheets of paper folded several times lengthwise, and rather long. Try folding over any piece of paper that way, and you'll get a long, narrow, compact set, admirably suited for stuffing the lining of a hat. And do you remember what he said besides? The manuscript was wrapped in tissue paper. Taken all together it was the obvious thing for Marks to use.'
`But Bitton said it was in the drawer.'
`I doubt that,' said Dr Fell. `Was it, Marks?'
Marks brushed a handkerchief over his damp forehead. 'N-no, sir,' he faltered. `It was lying there on the desk. I–I didn't think it was important. It was tissue-paper with some crackly stuff inside, the sort of thing they use to pack objects in cardboard boxes.'
`And then,' said Dr Fell, `you learned next day what you'd done. You learned it was worth thousands of pounds. And so you were afraid to tell Sir William what you'd done, because in the meantime the hat had been stolen.' He turned to Hadley. `I rather thought this was the case, from Sir William's description of Marks's behaviour when he interviewed him afterwards. Sir William made us an invaluable suggestion, which he thought was satiric. He said; "Do you think I go about carrying valuable manuscripts in my hat?" And that's precisely what he did.'
`And that,' Hadley said in a queer voice, `that was why Sir William's hat fitted him. It's what you meant by your hint'.'