'I'm afraid he is, Mr. Sheringham. What is it you want him to do?'
'Only tell the truth.'
'Well, that would be a nice change, for some of us,' said Mrs. Lefroy pleasantly. 'I don't think I've ever undertaken to tell so many lies in my life.'
Roger looked at her eagerly. 'You wouldn't tell one more, would you?'
'What would one more be among so many? I mean, what one in particular?'
Roger hesitated. Mrs. Lefroy really knew nothing, whatever she might think. Was it wise to let her see how very serious things actually were?
'Shut up, Roger, you ass.' Roger took his decision. He would have trusted very few women to this extent, but Mrs. Lefroy really was different.
'Would you say that you'd wiped the back of a chair on the roof last night, and incidentally the fingerprints off it, Mrs. Lefroy, when you know perfectly well that you never did anything of the kind?'
'Ach, Roger, come now. You can't ask her to do that. Do it yourself, man.'
'Is it important, Mr. Sheringham?'
'One might almost say that it's vital.'
'And Colin won't?'
'No.'
'But I tell you there's no need, Agatha. Roger can say it himself. There's no necessity at all for me or you to put ourselves in hot water on his account.'
'It isn't on my account,' Roger snapped. 'You know that perfectly well.'
'Mr. Sheringham must have some good reason for not saying he did it, Colin.'
'Of course I have, but Colin won't see it. The police would be more suspicious than they are already. They'd know I would never destroy evidence like that without knowing what I was doing; and that would make them do just what I want to prevent them from doing, and that is, ask themselves just what I was playing at. What I want is for someone to come forward and say he did it, who might never have realized what an important action it was. You understand that, surely? Because Colin doesn't.'
'Ach, yes, I do; but they wouldn't believe that I didn't know what I was doing, either. I did know, jolly well.'
'Now you're shifting your ground.'
'Well, it's true enough.'
'Anyhow, don't quarrel any more, you two,' said Mrs. Lefroy soothingly, 'because I'll say it. I can, quite conveniently, because I actually was on the roof last night soon after Ena had been found.'
'You were?' Roger said in surprise. 'I didn't know.'
'Yes, I was. I'm afraid I didn't tell the inspector so last night, because it didn't seem of the least importance; but as it happened, I wasn't in the ballroom when Colin came down to keep us penned in. I was . . . Anyhow,' said Mrs. Lefroy, 'I heard a lot of commotion on the stairs, so I went straight up to the roof. Osbert was there, and he told me what had happened.'
'Osbert's never mentioned that.'
'I don't expect,' said Mrs. Lefroy, 'that he remembers very much about it. But he probably would if I reminded him.'
'That's excellent.'
'Yes. So what exactly is it that I'm to confess to? Something about a chair, did you say?'
'It's like this, Mrs. Lefroy,' Roger explained rapidly. 'You know there was a chair lying under the gallows, which Mrs. Stratton must have used. For a certain reason which I needn't go into, Colin gave that chair a polishing with his handkerchief - thereby, incidentally, rubbing off any fingerprints that might have been on it, including Mrs. Stratton's own. The police have discovered that the chair has been wiped, and are choosing to put a sinister interpretation on the fact. It's essential that someone should own up to the wiping, laughing heartily and without the faintest notion that the act might be considered a serious one. That's what I want you to do.'
'Well, that seems quite easy,' Mrs. Lefroy said.
'I do like a woman who doesn't ask a lot of unnecessary questions,' said Roger with enthusiasm.
'Yes, but there seems one rather necessary one. Why did I do such a thing?'
'Why, indeed?' Roger said thoughtfully. 'Yes, it's essential to have a really good reason.'
'And one that will bring in the seat, as well as the back,' added Colin.
'Yes, the seat. I do wish ... By Jove, I've just remembered something. That's a bit of luck.'
'What?'
'Why, I was rather worried about that seat, wasn't I? But it's all right. I stood on it myself. So even if you did polish it a bit, that's bound to show. And now I come to think of it, the polishing's all to the good. It will have left the traces of slightly gritty feet; but it will have destroyed any awkward contrasts between flat heels and high ones. Yes, that is a bit of luck.'
'I'm glad there was some use in what I did,' Colin said drily.
'Do you know that I'm absolutely dying to ask a thousand unnecessary questions, Mr. Sheringham?' said Mrs. Lefroy. 'I should like you to know that, because I'm not going to ask a single one of them.'
'I'll tell Ronald what a magnificent woman you are,' Roger promised. 'He may have some idea, but he can't realize fully.'
'Agatha's a grand woman,' Colin agreed. 'But why did she wipe that chair?'
They looked at one another. It was very difficult to imagine why Mrs. Lefroy should have wiped the chair.
'It couldn't have had jam on it, or anything like that?' asked Mrs. Lefroy, not very hopefully.
'A wee dicky - bird?' suggested Colin.
Roger groaned. 'You wiped it so thoroughly,' he said. 'Why should anyone want to wipe a chair thoroughly on a roof?'
'Because of smuts,' Mrs. Lefroy said promptly. 'After all, my dress was white.'
Roger looked at her with admiration. Then his face fell.
'But you weren't going to sit on it For one thing it was on its side. For another, you wouldn't have been going to sit on that particular chair.'
'Yes. I came over queer, and had to sit on the nearest chair.'
'If you came over queer, you wouldn't have bothered to wipe it. Besides, what did you wipe it with? The skirt of your white dress? Not very convincing, I'm afraid.'
'Ach, Agatha never wiped it at all. Osbert wiped it for her, with his handkerchief. The man was as tight as a lord. He won't know whether he wiped fifty chairs last night or not.'
'Colin,' said Roger, 'I believe you've hit it. But wait a minute. Did Osbert wipe it on its side? Hadn't he the common politeness to pick it up?'
'Oh, yes,' said Mrs. Lefroy. 'But I knocked it over again when I got up.'
'Then why hasn't it got Osbert's prints on it?'
'Oh! Well, I picked it up myself, before he wiped it. And it hasn't got my prints on it, because I was wearing my velvet gloves.'
'So you were,' Roger said happily. 'And you asked Osbert to wipe it because it made a smutty mark on your white velvet glove when you picked it up.'
'Naturally I did. And I was just able to stand up, queer though I'd come over, till he'd done it. And all that fits beautifully, because there I was, actually on the roof with Osbert, while you and Ronald were with Ena downstairs. I'm afraid it was rather morbid of me to go and examine the gallows so soon, but there, I'm not ashamed of that.'
'This,' said Roger, 'looks to me like a very pretty piece of work. We'll rehearse it once, just to make sure that the details are perfect, and then we'll tell Osbert. Now, Mrs. Lefroy, you're you, I'm Osbert, and Colin isn't there. Here are the gallows, and this is the chair. We three have just gone down, and you've come up, to find Osbert in possession. He's told you what has happened, and you've walked over to the gallows. Yes, here's the rope, you see.'
'How dreadful,' murmured Mrs. Lefroy. 'Was she really . . . oh, Osbert, I feel horribly faint. I must sit down.' She picked up the chair. 'Oh, look at my glove. Have you got a handkerchief, Osbert? Just wipe the chair for me, will
