The therapists who work the warm room hours in Amsterdam

The grid above is the entire roster rather than a shortlist for tonight. Twenty-three is the number on the books; the number free on any given evening is smaller, and it moves with the week as much as with the weather.

Nobody on this roster is put on a rota. Each woman sets the hours she keeps, so the list that answers a message on a wet Tuesday in November is not the list that answers on the first warm Friday in May, and neither of them is short.

Naming a woman, or describing an evening

Both work, and the thread runs faster when you pick one. If a profile has already settled it, write the name and the hour. If it has not, say what the evening is: coming in soaked, stuck inside a heat that will not lift, two of you in a room with a slow radiator. The answer comes back with who is free for that hour, a figure, and an arrival window.

What the reply will not do is push a different name at you. If the woman you asked for is not free, that is what the message says, and the choice of what happens next stays with you.

Reading a profile before you write

Each page carries her age, the districts she covers, the languages she speaks, the formats she works in and her own rates for one guest and for a couple, with one therapist or with two. Photographs on a page are of the woman whose page it is, published with her agreement. Nothing on a profile describes what a session contains, because that is hers to say at the door and not the site's to promise.

Rates sit on the profiles rather than on a table of their own, since they are hers. Half of whichever figure applies confirms nearly every booking, and the rule for that is set out on the booking page.

What the house does with your choice

It arranges the hour, agrees it in writing, confirms it and says what it costs. It does not decide what happens in the room, and it does not speak for any woman on this roster about her limits. She does that herself, in the first minutes, in her own words. The formats page covers the work itself, and the questions page covers most of what is left.