Fred fumbled for his wand, after James had explained just what to do. Magical signatures, right, that was - he knew a spell to detect them, he just couldn't focus.
He took another wild look around, and aimed his wand at the second floor of the apartment across the road. Maybe if he went through the motions, a spell would come to him - and it did. He was relieved, and channeling his magic helped him to channel his emotions as well. He repeated the spell, more focused and calm this time, and there was a tiny pull. He tried again, this time at the houses on their side of the street. It was the same result.
"What - what if the whole area's been warded? How are we supposed to narrow it down from there!?"