Helena said: ‘Here you are, Gay.’ Darcey had already opened his case and held it out to her in his right hand. His left hand was in his trouser pocket. His posture was elegant and modish, out of keeping with his look of anxiety and watchfulness.

‘Where are your cigarettes?’ Alleyn asked and Gay said quickly: ‘It doesn’t matter, thank you. I’ve got one. I won’t bother. I’m sorry I interrupted.’

‘But where are they?’

‘I don’t really know what I’ve done with them.’

‘Where were you during the performance?’

She said impatiently: ‘It really doesn’t matter. I’ll look for them later or something.’

‘Gay,’ said Jacko, ‘was in the greenroom throughout the show.’

‘Lamprey will see if he can find them.’

The young constable said: ‘Yes, of course, sir,’ and went out.

‘In the greenroom?’ Alleyn said. ‘Were you there all the time, Miss Gainsford?’

Standing in front of her with his back to Alleyn, Darcey held a light to her cigarette. She inhaled and coughed violently. He said: ‘Gay didn’t feel fit enough to move. She curled up in a chair in the greenroom. I was to take her home after the show.’

‘When did you leave the greenroom, Miss Gainsford?’

But it seemed that Gay had half-asphyxiated herself with her cigarette. She handed it wildly to Darcey, buried her face in her handkerchief and was madly convulsed. PC Lamprey returned with a packet of cigarettes, was waved away with vehemence, gave them to Darcey and on his own initiative fetched a cup of water.

‘If the face is congested,’ Dr Rutherford advised from the sofa, ‘hold her up by the heels.’ His eyes remained closed.

Whether it was the possibility of being subjected to this treatment or the sip of water that Darcey persuaded her to take or the generous thumps on her back, administered by Jacko, that effected a cure, the paroxysm abated. Alleyn, who had watched this scene thoughtfully, said: ‘If you are quite yourself again, Miss Gainsford, will you try to remember when you left the greenroom?’

She shook her head weakly and said in an invalid’s voice: ‘Please, I honestly don’t remember. Is it very important?’

‘Oh, for pity’s sake, Gay!’ cried Helena with every sign of the liveliest irritation. ‘Do stop being such an unmitigated ass. You’re not choking: if you were your eyes would water and you’d probably dribble. Of course it’s important. You were in the greenroom and next door to Ben. Think!’

‘But you can’t imagine—’ Gay said wildly. ‘Oh, Aunty—I’m sorry, I mean, Ella—I do think that’s a frightful thing to suggest.’