Harry had soon mastered the Impediment Curse, a spell to slow down and obstruct attackers; the Reductor Curse, which would enable him to blast solid objects out of his way; and the Four-Point Spell, a useful discovery of Hermione’s that would make his wand point due north, therefore enabling him to check whether he was going in the right direction within the maze. He was still having trouble with the Shield Charm, though. This was supposed to cast a temporary, invisible wall around himself that deflected minor curses;
