The overnight, an eight hour block
An overnight is one fixed block of eight hours rather than an open-ended stay, booked as a single figure and always confirmed with half of it in advance.
An overnight here is a defined length, not a vague arrangement that ends when somebody wakes up. Eight hours, agreed in the thread with a start time like any other booking, and closing eight hours after that start. Knowing where it ends is what lets both sides relax inside it.
The figures
One guest with one therapist is 1,250 euros for the block. A couple with one therapist is 2,500. Two therapists with one guest are 2,880, and a couple with a therapist each is 5,760. Half of whichever line applies goes ahead once the hour is fixed, since the block always carries a deposit whoever is booking and however far ahead.
Why it always carries one
Eight hours is not one booking; it is the whole of an evening and most of a night, and nothing else can be put anywhere near it. A block of that size committed on a message alone would be a large piece of somebody's calendar resting on very little. Half of the figure sent in advance is what makes the commitment run in both directions.
What to think about before booking one
Whether you actually want eight hours, first of all. Guests who have not booked one before often find that three hours is the length they were describing. Beyond that, the practical things: a room you are staying in rather than borrowing, a building whose night entrance you can explain, and a start time you will still be awake for. A session that ends early is still paid at the block figure, so it is worth getting the length right in the thread. Each profile on the roster prints her own lines for the block.