But Hercule Poirot remained grave. 'And you are quite sure, Monsieur Harrison, that it is with petrol that Monsieur Langton ia going to destroy your wasps' nest?' 'Quite sure. Why?' 'I wondered. I was at the chemist's in Barchester this afternoon.

For one of my purchases I had to sign the poison book. I saw the last entry. It was for cyanide of potassium and it was signed for by Claude Langton.'

Harrison stared. 'That's odd,' he said. 'Langton told me the other day that he'd never dream of using the stuff; in fact, he said it oughtn't to be sold for the purpose.'

Poirot looked out over the roses. His voice was very quiet as he asked a question. 'Do you like Langton?'

The other started. The question somehow seemed to find him quite unprepared. 'I - I - well, I mean - of course, I like him.

Why shouldn't I?'

'I only wondered,' said Poirot placidly, 'whether you did.'

And as the other did not answer, he went on. 'I also wondered if he liked you?'

'What are you getting at, Monsieur Poirot? There's something in your mind I can't fathom.'

'I am going to be very frank. You are engaged to be married, Monsieur Harrison. I know Miss Molly Dearie. She is a very charming, a very beautiful girl. Before she was engaged to you, she was engaged to Claude Langton. She threw him over for you.'

Harrison nodded.

'I do not ask what her reasons were; she may have been justified.

But I tell you this, it is not too much to suppose that Langton has not forgotten or forgiven.'

'You're wrong, Monsieur Poirot. I swear you're wrong. Lang-ton's been a sportsman; he's taken things like a man. He's been amazingly decent to me - gone out of his way to be friendly.'

'And that does not strike you as unusual? You use the word

"amazingly", but you do not seem to be amazed.'

'What do you mean, M. Poirot?'

'I mean,' said Poirot, and his voice had a new note in it, 'that a man may conceal his hate till the proper time comes.'

'Hate?' Harrison shook his head and laughed.

'The English are very stupid,' said Poirot. 'They think that they can deceive anyone but that no one can deceive them. The sportsman - the good fellow - never will they believe evil of him.

And because they are brave, but stupid, sometimes they die when they need not die.' /

'You are warning me,' said Harrison in a low voice. 'I see it now - what has puzzled me all along. You are warning me against Claude Langton. You came here today to warn me…'

Poirot nodded. Harrison sprang up suddenly. 'But you are mad, Monsieur Poirot. This is England. Things don't happen like that here. Disappointed suitors don't go about stabbing people in the back and poisoning them. And you're wrong about Langton. That chap wouldn't hurt a fly.'

'The lives of flies are not my concern,' said Poirot placidly.

'And although you say Monsieur Langton would not take the life of one, yet you forget that he is even now preparing to take the lives of several thousand wasps.'

Harrison did not at once reply. The little detective in his turn sprang to his feet. He advanced to his friend and laid a hand on his shoulder. So agitated was he that he almost shook the big man, and, as he did so, he hissed into his ear: 'Rouse yourself, my friend, rouse yourself. And look - look where I am pointing. There on the bank, close by that tree root. See you, the wasps returning home, placid at the end of the day? In a little hour, there will be destruction, and they know it not. There is no one to tell them.

They have not, it seems, a Hercule Poirot. I tell you, Monsieur Harrison, I am down here on business. Murder is my business.

And it is my business before it has happened as well as afterwards.

At what time does Monsieur Langton come to take this wasps' nest?'

'Langton would never…'

'At what time?'

'At nine o'clock. But I tell you, you're all wrong. Langton would never…°

'These Englishl' cried Poirot in a passion. He caught up his hat and stick and moved down the path, pausing to speak over his shoulder. 'I do not stay to argue with you. I should only enrage myself. But you understand, I return at nine o'clock?'

Harrison opened his mouth to speak, but Poirot did not give him the chance. 'I know what you would say: "Langton would never," et cetera. Ah, Langton would never{But all the same I return at nine o'clock. But, yes, it will amuse me - put it like that - it will amuse me to see the taking of a wasps' nest. Another of your English sports' He waited for no reply but passed rapidly down the path and out through the door that creaked. Once outside on the road, his pace slackened. His vivacity died down, his face became grave and troubled. Once he drew his watch from his pocket and con-suited it. The hands pointed to ten minutes past eight. 'Over three quarters of an hour,' he murmured. 'I wonder if I should have waited.' His footsteps slackened; he almost seemed on the point of returning. Some vague foreboding seemed to assail him. He shook it off resolutely, however, and continued to walk in the direction of the village. But his face was still troubled, and once or twice he shook his head like a man only partly satisfied.

It was still some minutes of nine when he once more approached the garden door. It was a clear, still evening; hardly a breeze stirred the leaves. There was, perhaps, something a little sinister in the stillness, like the lull before a storm.

Poirot's footsteps quickened every so slightly. He was suddenly alarmed - and uncertain. He feared he knew not what.

And at that moment the garden door opened and Claude Langton stepped quickly out into the road. He started when he saw Poirot.

'Oh - er - good evening.' 'Good evening, Monsieur Langton. You are early.' Langton stared at him. 'I don't know what you mean.' 'You have taken the wasps' nest?' 'As a matter of fact, I didn't.' 'Oh!' said Poirot softly. 'So you did not take the wasps' nest.

What did you do then?' 'Oh, just sat and yarned a bit with old Harrison. I really must hurry along now, Monsieur Poirot. I'd no idea you were remaining in this part of the world.' 'I-had business here, you see.'

'Ohl Well, you'll find Harrison on the terrace. Sorry I can't stop.'

He hurried away. Poirot looked after him. A nervous young fellow, good-looking with a weak mouthl

'So I shall find Harrison on the terrace,' murmured Poirot.

'I wonder.' He went in through the garden door and up the path.

Harrison was sitting in a chair by the table. He sat motionless and did not even turn his head as Poirot came up to him.

'Ah! Mon ami,' said Poirot. 'You are all right, eh?'

There was a long pause and, then Harrison said in a queer, dazed voice, 'What did you say?'

'I said - are you all right?'

'All right? Yes, I'm all right. Why not?' 'You feel no ill effects? That is good.' 'Ill effects? From what?' 'Washing soda.'

Harrison roused himself suddenly. 'Washing soda? What do you mean?'

Poirot made an apologetic gesture. 'I infinitely regret the necessity, but I put some in your pocket.'

'You put some in my pocket? What on earth for?'

IIarrison stared at him. Poirot spoke quietly and impersonally like a lecturer coming down to the level of a small child.

'You see, one of the advantages, or disadvantages, of being a detective is that it brings you into contact with the criminal classes. And the criminal classes, they can teach you some very interesting and curious things. There was a pickpocket once - I interested myself in him because for once in a way he has not done what they say he has done - and so I get him off. And because he is grateful he pays me in the only way he can think of - which is to show me the tricks of his trade.

'And so it happens that I can pick a man's pocket if I choose without his ever suspecting the fact. I lay one hand on his shoulder, I excite myself, and he feels nothing. But all the same I have managed to transfer what is in his pocket to my pocket and leave washing soda in its place.