A practical person like herself wasn’t going to be done that way. She’d go out by the front door, walk round to the side entrance and – but, no, that wouldn’t work either. If she opened the gate and bolted it on the inside, she’d simply find herself bolted inside the yard. The only thing was to climb out of the window. She tried desperately to undo the window screws, but they had seized up from years of disuse and she couldn’t shift them. Trembling now, she sat down on the edge of her bed and lit a cigarette. For the first time in her life she was in an insecure place by night, alone in a London flat, with nothing to separate her from hordes of rapacious burglars but a feeble back door lock which any type of a thief could pick open in five minutes.

How criminally careless of Mrs Swanson not to have provided the door between the bed-sitter and the kitchen with a lock! There was no heavy piece of furniture she could place against the door. The phone was by her bed, of course. But if she heard a sound and dialled for the police was there a chance of their getting there before she was murdered and the place ransacked?

What Mrs Swanson had provided was one of the most fearsome-looking breadknives Della had ever seen. She fetched it from the kitchen and put it under her pillow. Its presence made her feel slightly safer, but suppose she didn’t wake up when the man came in, suppose . . .? That was ridiculous, she wouldn’t sleep at all. Exhausted, shaken, feeling physically sick, she crawled under the bedclothes and, after concentrated thought, put the light out. Perhaps, if there was no light on, he would go past her, not know she was there, make his way into the main part of the house, and if by then she hadn’t actually died of fright . . .

At twenty minutes past one, when she had reached the point of deciding to phone for a car to take her to an hotel, the side gate clicked and Rosamund entered the yard. Della fell back against the pillows with a relief so tremendous that she couldn’t even bother to go out and check the bolts. So what if it wasn’t bolted? The man would have to pass Rosamund first, kill her first. Della found she didn’t care at all about what might happen to Rosamund, only about her own safety.

She sneaked out at half-past six to put the knife back, and she was sullenly eating her breakfast, the flat immaculate, when Rosamund appeared at eight.

‘I missed the last bus. I had to get a taxi.’

‘You could have phoned.’

‘Goodness, you sound just like my mother. It was bad enough having to get up and . . .’ Rosamund blushed and put her hand over her mouth. ‘I mean, go out and get that taxi and . . . Well, I wasn’t all that late,’ she muttered.