They read the clause together at the desk and Mione finds the thing she missed, because there is always a thing she missed.

MioneThe keeper shall not sleep and the witness shall not lie. That is two. But the room will not open on two, it says so in the margin.

The margin note is in a hand four hundred years old and it says a chamber kept alone keeps nothing.

CorvinaThen take the Malfoid girl. She has been sleeping badly since the war and she will not refuse a night where she is useful.