Dorothy plied her needles energetically.

‘In short,’ she said, ‘they all had a motive to poison her.’

‘All except George Channing, the corned beef millionaire,’ agreed Rosemary. ‘Unfortunately they all had an alibi, too.’

‘Even Rosenstein?’

Dorothy pointed to the Jew, who was still muttering urgent phrases into the phone.

‘He seemed the most likely suspect for some time,’ Rosemary admitted. ‘Samuel Rosenstein had every reason to wish Hilary Bryant dead, since she was blackmailing him over the matter of his shady share-dealings. Moreover it was he who passed her the poisoned glass of wine at dinner that evening…’

‘…and then knocked over his own glass, staining Grace Lebon’s dress red in an eerie presage of the horrors to come…’

‘.. except that it wasn’t his own but the poisoned drink,’ Rosemary continued, ‘which he was forced to spill deliberately in order to avoid having to drink it himself when Hilary, suspecting his murderous intent, cunningly switched their glasses. Yes, Samuel Rosenstein certainly planned Hilary’s death, but he did not in fact kill her.’

Dorothy gazed eagerly at her friend.

‘Then who did?’ she breathed.

The door swung violently open and a thickset woman wearing stained blue overalls came rushing into the lounge.

‘Where the fuck’s Channing?’ she bellowed.

No one moved, no one spoke. The woman stood panting in the centre of the room. Her skin was blotchy and uneven, her hair grizzled. Her eyes took in each of the residents in turn: the colonel with his paper, the elderly hypochondriac swathed in blankets, the gay couple by the window, the financier holding the telephone, the languid aristocrat at the piano, the mild-mannered clergyman reading in the corner.