She is very busy in her room. She comes out to raid the kitchen, for biscuits, for a teabag. 'Can I have those oranges, Mummy? This bag of coffee beans?' She washes her fancy teaset, which has been gathering dust on the shelf. 'Have we got a bigger tray than this?' I give her the big square chopping board.
'What are you doing in there?'
'Never mind!' The door shuts firmly behind her.
She brings me an umbrella and asks me to put it up. 'Because I don't want the bad luck.'
'I don't want bad luck either!' But I put it up anyway, because that's what mothers do.
'Can I borrow your phone?'
'How long for?'
'A day or two?'
She looks mysterious. 'To be part of a time machine.' The door closes again.
Presently she comes out and gives me a big, silent hug.
Without thinking, I say, 'Bye...'
'Goodbye, goodbye!' cries her sister, agog.
She breaks away, passionately angry. 'Why did you have to say that? Why did you say goodbye? I'm not going anywhere!'
'You said you were making a time machine!' Her sister dances about.
She storms away, slams her door. Her sister crouches in the hallway, whispers to me, 'If we see a flashing light come under her door, then we'll know.'
'Then we're in trouble,' I say. I usher her sister away.
And I feel sorry; I think I understand. If only we hadn't put it into words, if we could only have let that mysterious silence be -- that silence where fragile belief can unfurl -- it would have been all right. But our words wrecked everything, made her face the fact that it wasn't true, that her time machine was only an umbrella, some oranges and a mobile phone; that the Doctor wasn't going to land in her bedroom for afternoon tea.
Later that evening she cries her heart out, because the Brigadier died before the Doctor could see him again, because he'd put out the extra glass of brandy every night in vain. She cries for the Brigadier's disappointment; she cries for the Brigadier's hope. 'It's too sad,' she sobs.
I hug her tight. 'Maybe the Doctor went back, one last time. He does have a TARDIS.'
'But he's dead, Mummy! You can't visit the dead.'
You also can't visit a person who is imaginary; but, being my daughter's mother, it doesn't even cross my mind to say it. Tears shine on her cheeks, and I say nothing at all.