At that, Narcissa takes a sudden step forward as she tries to think on her feet - this doesn't seem like the very best idea under the circumstances, but how to stop it without inciting Bellatrix's rage in her own direction? She doesn't fancy being choked by her own sister.

"There's chaos here already," she says, her hand around Bellatrix's wrist - not tight, not tense or anxious, a restraint but one she takes pains not to be sharp about. "If it is only the two of us, shouldn't we know with what we contend before we allow them to know us?"