Neville halted at the boundary line. His father skidded into place alongside him. Moments later the other four members of Harry's Inner Circle were ranged in a line beside them. All their wands were drawn and throbbing with anxious energy. Neville stepped forwards and cast a rune into the air. He filled it with his magic and sent it at the boundary line. When it returned he would know if it was friend or foe, encroaching on the other side of the ward, trying to get in.