The shouting already set the hair on the back of his neck standing up, but when they saw Lucius shouting at nothing at all, the Lucius he had known would rather have died then act like this. All at once, Draco's words in the house seemed much too real, and Remus felt a tendril of true worry for the man go through him.

Enough that he actually stepped forward quickly, acting more like the teacher he had been (and a member of the Order) by making sure that Draco was half-behind him. Still visible, if Lucius were more to recognize him, but far more worried that Lucius might not at all. His wand didn't lower, but he kept his voice calm.

"Lucius. Draco and I were concerned when you didn't return." Pointedly using his son's name, trying to get the other to focus.