Sister: A Novel by Rosamund Lupton

the most probable.’
    ‘But Amias said the phone calls were real, when he reported her missing, didn’t he?’
    ‘But he was never actually there when she got one of the phone calls.’
    I thought about telling him that your phone was unplugged when I arrived. But that didn’t prove anything. The calls could still have been delusional.
    ‘Tess’s psychiatrist has told us that symptoms of post-natal psychosis include delusions and paranoia,’ DS Finborough continued. ‘Sadly, many of those women suffering also have thoughts of harming themselves and tragically some actually do.’
    ‘But Tess didn’t.’
    ‘A knife was found next to her body, Beatrice.’
    ‘You think she carried a knife now?’
    ‘It was a kitchen one. And it had her fingerprints on it.’
    ‘What kind of kitchen knife?’
    I’m not sure why I asked, maybe some dimly remembered seminar on the questioner taking authority. There was a moment of hesitation before he replied, ‘A Sabatier five-inch boning knife.’
    But I only heard the word ‘Sabatier’, maybe because it distracted me from the ugly violence of the rest of the description. Or maybe the word ‘Sabatier’ struck me because it was so absurd to think you would own one.
    ‘Tess couldn’t possibly have afforded a Sabatier knife.’
    Was this conversation degenerating into farce? Bathos?
    ‘Maybe she got it from a friend,’ suggested DS Finborough. ‘Or it was a gift from someone.’
    ‘She would have told me.’
    Sympathy tempered his look of disbelief. I wanted to make him understand that we shared the details of our lives, because they were the threads that braided us so closely together. And you would have been certain to tell me about a Sabatier knife, because it would have had the rare value of being a detail in your life which tied directly into mine - our lives sharing top-end kitchenware.
    ‘We told each other the little things, that’s what made us so close I think, all the small things and she’d have known I’d want to hear about a Sabatier knife.’
    No, I know, it didn’t sound convincing.
    DS Finborough’s voice was sympathetic but firm, and I briefly wondered if, like parents, the police believed in setting parameters. ‘I understand how hard this must be for you to accept. And I understand why you need to blame someone for her death, but—’
    I interrupted with my certainty about you. ‘I’ve known her since she was born. I know her better than anyone else possibly could. And she would never have killed herself.’
    He looked at me with compassion; he didn’t like doing this. ‘You didn’t know when her baby died, did you?’
    I couldn’t answer him, winded by his punch to a part of me already bruised and fragile. He’d told me once before, indirectly, that we weren’t close, but then it came with the upside that you had run off somewhere without telling me. Not being close had meant you were still alive. But this time there was no huge pay-off.
    ‘She bought airmail stamps, just before she died, didn’t she? From the post office on Exhibition Road. So she must have written to me.’
    ‘Has a letter from her arrived?’
    I’d asked a neighbour to go in and check the apartment daily. I’d phoned our local post office in New York and demanded they search. But there was nothing; and it would surely have arrived by now.
    ‘Maybe she meant to write to me, but was prevented.’
    I heard how weak it sounded. DS Finborough was looking at me with sympathy.
    ‘I think Tess was going through hell after her baby died,’ he said. ‘And it isn’t a place anyone could join her. Even you.’
    I went through to the kitchen, ‘stropping off’ as Mum used to call it, but it wasn’t a strop, more of an absolute physical denial of what he was saying. A few minutes later I heard the front door shut. They didn’t know that words could seep through your badly fitting windows.
    WPC Vernon’s voice was quiet. ‘Wasn’t that a little . . . ?’ She