‘Is Edward’s study the Ark of the Tabernacle of the Lord,’ cried Dr Ackrington in a fury, ‘that Questing should be subdued in it? Why this perpetual itch to herd people together in Edward’s study, which, when all’s said and done, is no bigger than a lavatory and rather less comfortable? Will you listen to me? Will you indulge me so far as to keep quiet while I speak to Questing, here, openly, in the presence of you all?’

Dikon’s attention was momentarily diverted by Gaunt, who said in a fierce whisper: ‘If you forget a syllable of that speech I shall sack you.’

The Claires were all speaking together again but their expostulations died out when Dr Ackrington cast himself back in his chair, turned up his eyes and began to whistle through his teeth. After an uncomfortable silence Mrs Claire said timidly: ‘I’m sure there’s been some mistake.’

‘Indeed?’ said her brother. ‘Do you mean that Questing miscalculated and that Smith has no right to be alive?’

‘No, dear.’

‘What was Smith saying about lights?’ asked Colonel Claire suddenly. ‘I didn’t catch all that about lights.’

‘Will someone explain to Edward about railway signals?’ Dr Ackrington asked dangerously, but Colonel Claire went on in a high complaining voice. ‘I mean, suppose Questing didn’t happen to notice the signals.’

‘You, Edward,’ his brother-in-law interrupted, ‘are the only person of my acquaintance from whom I can conceive such a display of negligence, but even you could scarcely fail to glance at a signal some twenty-two yards in front of your nose before inviting a man to risk his life on a single-track railway bridge. I find it impossible to believe that Questing didn’t act deliberately and I have good reason to believe that he did.’

There was another silence broken unexpectedly by Geoffrey Gaunt. ‘In fact, Dr Ackrington,’ said Gaunt, ‘you think we have a potential murderer among us?’

‘I do.’

‘Strange. I’ve never thought of a murderer being an insufferable bore.’

Barbara gave a yelp of unhappy laughter.

‘Wait on!’ said Simon. ‘Listen!’

They all heard Questing’s car come down the drive. He drove past the windows and round the house to the garages.

‘He’ll come in here!’ Barbara whispered.

‘I implore you to leave him to me, Edward.’

Colonel Claire threw up his hands. ‘Shall Barbie and I—?’ Mrs Claire began, but her brother silenced her with an angry flap of his hand. After that nobody spoke and Questing’s footfall sounded loud as he came round the house and along the verandah.

Perhaps Dikon had anticipated, subconsciously, a sinister change in Questing. Undoubtedly he experienced a shock of anticlimax when he heard the familiar and detestable inquiry.

‘Well, well, well,’ said Mr Questing, beaming in the doorway, ‘how’s tricks? Any dinner left for a little feller? Am I hungry or am I hungry! Good evening, Mr Gaunt. And how’s the young gentleman?’