Secret Diary Of A Call Girl - Billie Piper plays Belle de Jour

Thursday 11 October 2007 10:00pm - 10:30pm on ITV2.

Belle is on her way to an 'all nighter'. The client has booked her for the whole night and so it's important that she manages her time well. Belle tells us that apart from the sex toys, the most important piece of equipment she needs is a watch.

She greets Ashok, a regular client she's very fond of. After a drink they have sex and Ashok soon nods off. Belle gets bored. She explains she can never sleep on an all night job so she has to find other things to do to while away the time: call Ben who thinks she's calling bored from the office; read a book; rearrange the hotel fruit bowl.

But after a while she's stir crazy so she goes down to reception. When she goes for a drink in the bar, she's approached by a man who works out she's an escort. And he asks to book her.

She can't can she? She can't two time her client? With the help of the friend on the front desk, she decides she can probably risk it. So she's exasperated to find out that this client prides himself on having great sexual stamina.

In fact he can go on and on and on and on. What's she going to do? Ashok could wake any minute. So she goes for an old trick of the trade which usually works a treat.

So when Ashok wakes up, Belle is right beside him in bed.

Producer Chrissy Skinns explains the development as the series continues, "We have created a dramatic narrative and the stories each week reveal something about Belle's life: from literally what her work day entails, to the difficulties of balancing her professional life with her personal life, which is mainly focused on her relationship with her best friend, Ben."

She continues: "London was a big part of our shoot.

We wanted to show the capital in a celebratory way, appreciating what it has to offer. So often London is shown as a gritty, grungy sort of city but in Secret Diary of a Call Girl it is a grown up, cosmopolitan place to be - rather like New York is reflected in Sex in the City.

Inevitably, locations such as upmarket hotels, were really important to the series in order to show the sexy, not seedy, side of London."