"You will have to live partly as a muggle, yes." Sirius frowns a bit at the "you", but he supposes Remus said he would help  find  Harry, not  raise  him."You can’t disappear from the wizarding world completely, of course, because that will be suspicious as well. But you can’t live with Harry at the flat, everyone knows you have it, and it’s hooked up to the floo and everything. You’ll need another place where Harry can go out and make friends and all in the muggle world." Remus reaches a hand back clumsily to pat the air near Sirius. "There, there, you’ll have time," Remus says, "we still need to find him, and that will give you plenty of practice being a muggle."