Sloane Square escorts in SW1W and SW3, timed around the evening's curtain

The Royal Court Theatre stands on the east side, a red brick Victorian playhouse known for new writing, with a bar and restaurant below where audiences argue about the play afterwards. Across the square, Peter Jones fills the west side behind one of Britain's earliest glass curtain walls, built in the 1930s. Between them the fountain shows Venus kneeling above a relief of Charles II and Nell Gwynne, and the benches under the trees make a pleasant place to wait on a dry evening.

A few minutes' walk away are the square's other rooms. Cadogan Hall on Sloane Terrace, once a church, is now a concert hall with an orchestra in residence. Duke of York Square, just along the King's Road, has the Saatchi Gallery and a paved piazza of restaurant terraces. Holbein Place leads south east towards Pimlico, and Lower Sloane Street runs down to the Royal Hospital.

These are the doors companions come through most often around the square. They are listed as addresses; no formal link exists between the agency and any of them.

Sloane Square Hotel stands on the square itself, practical and perfectly placed for anyone holding theatre tickets. 11 Cadogan Gardens occupies a rambling Victorian townhouse a few minutes to the north west, all corridors and staircases. Up Sloane Street, The Cadogan is the grand one, a Belmond hotel whose building took in the former home of Lillie Langtry. Beaverbrook Town House, on the same street but nearer the square, is newer, small and quietly theatrical inside.

Flats in the red brick mansion blocks of Sloane Gardens and the houses of Cadogan Gardens are visited on the same terms, once the flat number and your booking name have been checked.

Climb the stairs at Sloane Square station, served by the Circle and District lines, and the Royal Court is beside you, about 1 minute from the square. Victoria, with the Victoria line, the Circle and District lines and main line trains, is about 10 minutes' walk east.

A guest arriving at Victoria by rail has a simple choice between a short taxi ride and a pleasant walk through Eaton Square and along Cliveden Place to a hotel near the fountain.

Evening performances around the square usually begin between seven and eight, and that sets the shape of the booking. Message the desk earlier in the day with the companion you have in mind, the meeting time and where you would like to meet: the theatre bar, a table on the square or your hotel. Replies come within 10 to 15 minutes, and the booking is confirmed once the name you give has been matched to a hotel room or an address.

The clock starts when you meet, not when the lights go down, so allow for a drink first. For a standard hotel or residence booking the desk takes 25 percent ahead by bank transfer, and the balance is settled on the night in cash or by transfer. Stay the night, bring her to an event or take her travelling, and the deposit becomes half the fee, with its travel portion non-refundable. For same evening requests with no tickets involved, she is usually at the door inside the hour.

Theatregoers who read the reviews and booked the seats weeks ago. Concert audiences for Cadogan Hall. Guests at the Sloane Street hotels who spent the day between the boutiques and want an evening with more conversation in it. Residents of both sides of the square who prefer to host at home. Sloane Square guests are, on the whole, planners, and the companions who suit them best are well read, punctual and comfortable in a theatre bar.

Half past six: a glass of something at The Botanist on the corner of the square, its windows looking straight onto the fountain. Seven fifteen: across to the Royal Court and into your seats. Around a quarter to ten: out into the square again and a few steps to Colbert, a grand café where supper after a play is something of a local habit.

Half past ten: the short walk back to the hotel. Four hours from the first glass is the dinner date, £900. A guest who wants company only for supper after the play can book two hours for £500, and concert nights at Cadogan Hall follow the same shape.

Three companions live in Chelsea, a few minutes west along the King's Road: Cindy, Michelle and Stacy. East of the square, Belgravia is home to Lea, Patricia and Violetta, and to the south east, Pimlico is home to Lucy and Roxi.

Eight companions within a short ride make Sloane Square one of the best supplied corners of the map, and the rest of the gallery covers it on the same fees.

West, Chelsea runs the length of the King's Road. North west, by way of Sloane Avenue, are South Kensington and its museums. The SW3 postcode guide covers the Chelsea side of the square on a single page.