I wouldn't call it a 'fool's errand' to set a friend's mind at ease, but I do understand. Do you want me to check the obvious places for Regulus? I did open the Floo and speak with St Mungo's, who assure me he's not been admitted there. We both know there are several other possibilities that I could check if it would make you feel better. Of course, if he's any of those places, he'd as soon I didn't find him and drag him out.