Susan did as she was told. Harry threw off his cloak and Susan watched with bulging eyes. Harry's head was covered with a balaclava made of some kind of animal hide. It looked snake-like, scaly. Maybe basilisk. It was scored with strange symbols and markings which glowed and hummed as they caught the light. They coated Harry's head with a sort of film of heaving magical energy that was so intense Susan could feel it from her seat several feet away. Then Harry flicked out his wand. A wave of magical power swept the room as if wand and hand had fused. It made Susan's hair stick on end and the skin on her neck crept with sensation. She was a mix of wary and completely safe. It was utterly jarring.