Malfoid does the arithmetic before anyone else does: two witnesses have given something and one has not, and the one who has not is the one the stone is waiting on.

MalfoidGet up on the altar step. I am not doing this on a stone floor at my age and I am not having it written down that I was reluctant.

She is not reluctant and she does not let you be either, and the top step of a chapel altar is exactly as cold as it looks until it is not.

MalfoidDo not look at her. Look at me. She has an hour to be brave in and she does not need an audience for it yet.