‘The chain,’ said Peter. ‘Now, where-?’

‘Oh, yes.’ Mr Goodacre took up his thread again. ‘I was about to say, that is certainly a new chain. The old one was of brass to match the pot, whereas this-’

‘Peter!’ said Harriet, involuntarily.

‘Yes,’ he said, ‘I know now.’ He seized upon the ornamental drain-pipe, tossed the pampas-grasses out of it and tilted it up, just as Crutchley came in-this time with the man Bill-and advanced upon the other settle.

‘If you don’t mind, guv’nor.’

Peter jerked the pipe swiftly back and sat on it.

‘No,’ he said. ‘We haven’t finished here. Take yourselves off. We must have something to sit on. I’ll make it right with your employer.’

‘Oh!’ said Bill. ‘Well-right y’are, guv’nor. But mind you, this job’s got to be done today.’

‘It will be,’ said Peter.

George might have stood out; but Bill evidently possessed a more sensitively balanced temperament or a livelier eye to the main chance. He said submissively, ‘Right-ho, guv’nor,’ and went out, taking Crutchley with him.

As the door shut, Peter lifted the drain-pipe. At the bottom of it lay a brass chain, curled together like a sleeping serpent.

Harriet said: ‘The chain that came down the chimney.’

Peter’s glance swept over her as though she had been a stranger.

‘A new chain was fixed up and the other one hidden up the chimney. Why?’ He lilted the chain and looked at the cactus as it hung centred over the radio cabinet. Mr Goodacre was deeply intrigued.

‘Now that,’ he said, taking the end of the chain in his hand, ‘looks remarkably like the original chain. See. It is darkened with soot, but it’s quite bright when you rub it.’

Peter dropped his end of the chain, leaving it dangling in the vicar’s hand. He picked out Harriet from the rest and said to her, as though propounding a problem to the brightest-looking of a not-too-hopeful class:

‘When Crutchley had watered the cactus, which he had watered the week before and which should only be watered once a month-’

‘-in the colder weather,’ said Mr Goodacre.

‘-he was on the steps here. He wiped the pot. He got down. He put back the steps over here by the clock. He came back here to the cabinet. Can you remember what he did next?’

Harriet shut her eyes, once more seeing the room as it had been on that strange morning.

‘I believe-’

She opened them again. Peter laid his hands gently, one on each side of the cabinet?

‘Yes-he did. I know he did. He pulled the cabinet forward to bring it centrally under the pot. I was sitting quite close to him at the end of the settle-that’s why I noticed.’

‘I noticed it too. That’s the thing I couldn’t remember.’

He pushed the cabinet gently back, moving forward with it so that the pot now hung directly over his head and about three inches above it.

‘Dear me,’ said Mr Goodacre, surprised to discover that something of importance was apparently going on, ‘this is all very mysterious.’

Peter made no reply, but stood gently lifting and letting fall the lid of the radio cabinet. ‘Like this,’ he said, softly. ‘Like this… This is London calling.’

‘I’m afraid I’m being very stupid,’ ventured the vicar again.

This time Peter looked up and smiled at him.

‘Look!’ he said. He put up his hand and lightly touched the pot, setting it gently swinging at the end of its eight-foot chain. ‘It’s possible,’ he said. ‘My God! it’s possible. Mr Noakes was about your height, wasn’t he, padre?’

‘Just about. Just about. I may have had the advantage of him by an inch, but not more.’

‘If I’d had more inches,’ said Peter, regretfully (for his height was a sensitive point with him), ‘I might have had more brains. Better late than never.’ His eye roamed the room, passed over Harriet and the vicar and rested on Bunter. ‘You see,’ he said, ‘we’ve got the first and last terms of the progression-if we could fill in the middle terms.’

‘Yes, my lord,’ agreed Bunter, in a colourless voice. His heart had leapt within him. Not the new wife this time, but the old familiar companion of a hundred cases-the appeal had been to him. He coughed. ‘If I might make a suggestion, it would be as well to verify the difference in the chains before we proceed.’

‘Quite right, Bunter. Clear as you go. Get the steps.’

Harriet watched Bunter as he mounted and took the brass chain that the vicar mechanically handed to him. But it was Peter who heard the step on the stair. Before Miss Twitterton was in the room he was halfway across it, and when she turned from shutting the door after her, he stood at her elbow.

‘So that’s all seen to.’ said Miss Twitterton brightly. ‘Oh, Mr Goodacre-I didn’t think I should see you again. It is nice to think you’re having Uncle William’s cactus.’

‘Bunter’s just coping with it,’ said Peter. He stood between her and the steps and his five-foot nine was an effectual screen to her four-foot eight. ‘Miss Twitterton. if you’ve really finished, I wonder if you would do something for me?’

‘But of course-if I can!’

‘I think I must have dropped my fountain-pen somewhere in the bedroom, and I’m rather afraid one of those fellows up there may put his foot on it. If I might trouble you-’

‘Why, with pleasure!’ cried Miss Twitterton, delighted that the task was not beyond her powers. ‘I’ll run up and look for it at once. I always say I’m remarkably good at finding things.’

‘It’s extraordinarily kind of you,’ said Peter. He manoeuvred her gently to the door, opened it for her, and shut it after her. Harriet said nothing. She knew where Peter’s pen was, for she had seen it in the inner breast pocket of his coat when she was looking for cigarettes, and she felt a cold weight at the pit of her stomach. Bunter, who had slipped quickly down from the steps, stood, chain in hand, as though ready to put the gyves on a felon when he heard the word. Peter came back with urgency in his step.

‘Four inches difference, my lord.’

His master nodded.

‘Bunter-no, I shall want you.’ He saw Harriet and spoke to her as though she had been his footman. ‘Here, you, go and fasten the door at the top of the back stair. Don’t let her hear you if you can help it. Here are the house-keys. Lock the doors, front and back. Make sure that Ruddle and Puffett and Crutchley are all inside. If anyone says anything, those are my orders. Then bring the keys back-do you understand?… Bunter, take the steps and see if you can find anything in the way of a hook or a nail in the wall or ceiling on that side of the chimney-place.’

Harriet was out of the room, and tip-toeing along the passage. Voices in the kitchen and a subdued clinking told her that lunch was being got ready-and probably eaten. Through the open door she glimpsed the back of Crutchley’s head-he was tilting a mug to his lips. Beyond him stood Mr Puffett, his wide jaws moving slowly on a large mouthful. She could not see Mrs Ruddle, but in a moment her voice came through from the scullery. ‘See, it was that there Joe, plain as the nose on ’is face, and goodness knows that’s big enough, but there! ’e’s too much taken up with ’is good lady…’ Somebody laughed. Harriet thought it was George. She scurried past the kitchen, ran up the Privy Stair, locking the back door as she went, and found herself, panting, more with excitement than haste, at the door of her own room. The key was on the inside. She turned the handle softly and crept in. Nothing was there but her own boxes, packed and waiting, and the component parts of what had been the bed, stacked ready for removal. In the next room she could hear little scuffling sounds, and then Miss Twitterton chirping agitatedly to herself (like the White Rabbit, thought Harriet): ‘Oh, dear, oh, dear! what has become of it?’ (or was it, ‘what will become of me?’). For a flash of time Harriet stood, her hand already on the key. If she were to go in and say, ‘Miss Twitterton, he knows who killed your uncle, and…’ Like the White Rabbit-a white rabbit in a cage…