The mission: Child's play? No, not really.

Nicholas Barber tries to keep a six-year-old amused - for a whole afternoon

his week's Mission landed on my doorstep, almost literally. I'd once remarked to my friend Bart that if he and his wife ever fancied an afternoon to themselves, I could look after their daughter. We said no more about it - until one day when the three of them had come over for lunch, and the parents announced after the meal that they were off to an exhibition. They left me with no toys, no games, no books, no instructions and one six-year-old. By the time I'd recovered the power of speech, they were long gone.

I should stress at this point that Josie is as bright, happy and well- behaved a child as you could ever hope to have dumped on you at a moment's notice. But she does have her limits and an afternoon's chatting is beyond her. I ransack the flat for amusements, but neither Pictionary nor poker seems appropriate, and I can tell after five minutes of rolling a tennis ball back and forth across the carpet that Josie's heart isn't really in it.

We set off for the children's playground. All of a sudden, I'm shaken by a nervous sense of unearned responsibility that I haven't experienced since a man in Corfu let me hire a moped with neither experience, driving licence nor helmet. "What happens if she gets broken," I wonder. I start to see every car and every dog as a potential threat.

Soon we're enjoying ourselves too much to worry. Josie's favourite game requires me to chase her around a climbing frame and then fall over, and I don't see why we can't continue in this only mildly painful manner for hours. Then, abruptly, we have to stop. Josie needs to go to the toilet. Now. If not before. She explains as coyly as she can that in similar emergencies, Mummy sometimes angles her over some bushes and lets her sprinkle. I explain as coyly as I can that that ain't going to happen, so she'd better hold on until we're back at the flat.

We make it in the nick of time. While Josie's in the bathroom, I sprint to the corner shop to buy some felt-tips and crayons. Josie is not as grateful as I'd hoped. "Why did you get those?" she enquires. It's the unmalicious innocence of the question that makes it so withering. Remembering how taken she was with Disney's Hercules cartoon, I try to interest her by sketching a square-jawed muscle-man wearing a skirt. Josie humours me. "Is it Daddy?" she asks. This is particularly hurtful, as Daddy is a bespectacled academic. I've never seen him in a skirt either, although of course I don't know everything he gets up to in his own home.

Still, the drawing reminds me that I've got a video of Disney's Robin Hood somewhere, which I was given for my 25th birthday. It seemed like a weird present at the time, but this afternoon it keeps Josie entertained until her parents return. I don't care if it's a cop-out. I just remember a verse from "Being A Dad" by Loudon Wainwright. "It's as hard as it looks, you've gotta read 'em dumb books, and you end up despising Walt Disney." Au contraire, Loudon. I don't know what I'd have done without him