[She looks down just as he's looking around, and she sees - for Merlin's sake, Grigori, that's Grigori and his group of whoever it is that follow him around, half the bloody Quidditch team, how fantastic. This is a disaster waiting to happen, her twin has been chomping at the bit ever since Black broke his nose, and so she takes her wand from her pocket and uses a quick little charm to knock on the top of Black's head, knock knock, look up.]

Hell.

[Grigori doesn't see him yet, this could end not quite so badly-]