Heart of the Guardian

15. Mundungus Fletcher

Potter did not question Snape's suggestion they head back to Hogsmeade. They first walked back to Snape's quarters to gather light summer traveling cloaks. Snape suggested the boy bring the invisibility cloak. He watched as Potter locked two of the three wands in the trunk, now set against a wall, and noted his anxious look back as he left the room.

Snape put out a hand to stop the boy, and stepped past him into the room. He paced the room's perimeter clockwise, trailing a hand along the wall. When he arrived back at the door, he made a complicated series of elegant motions with his wand hand, and snapped his fingers. Potter watched curiously. As they left Snape's quarters, he stopped the boy again, repeated the elegant gesture and the snap, his lips moving soundlessly in concentration, due to being somewhat distracted by the boy's intent gaze. Then he turned and gestured to Potter to follow him.

"You were..." The boy waved a hand, looking for the right word.

"Warding our space, yes," Snape said, missing the startled half-smile that flitted across the boy's face. "It keeps out intruders – rather more effectively than a lock, especially with people around like the Weasley twins... or a certain trio..." He looked at Potter meaningfully and the boy grinned. "It also keeps out house elves, even the headmaster or headmistress. Only the wizard who sets it or those he keys to it can enter once the ward is set."

"What happens if someone else tries?"

"That depends on how the ward is set. It might repel, Obliviate, or even kill the intruder, with or without warning."

The boy gulped. "And... how did you set this one, Sir?"

Snape looked at him without answering, and the boy turned pale.

"Not to worry, Potter. No one will intrude."

"Did you... did you set a warning, Sir?" The boy asked. Snape nodded, and he relaxed.

"For house elves and ghosts. No one else."

"But what if Professor McGonagall..."

"Professor McGonagall is familiar with both this spell and my signature. Furthermore, she is familiar with my habits, which have been to ward my space... for obvious reasons. And she is in London. It is unlikely she would return early without sending word."

The boy paced at his side for a few moments. "You said Professor McGonagall knows your 'signature', Professor."

"Yes."

"Explain," he said, not quite a demand, and Snape was struck by the realization that the wizard at his side had grown immeasurably the past year... was nearly a man. How could he not be?

"Magic leaves traces," he said. "If you have met a wizard or witch and seen them work even the barest spell, if you know what to look for, you can identify their... unique signature, for lack of a better term."

The boy thought some moments. "That's why I recognized your Patronus," he said. "I knew it was familiar... and safe... but I couldn't put my finger on it. I just didn't think it could be..."

The word safe echoed between them again, making Snape's heart ache, though not nearly as much as before, leaving a rather warm imprint.

Snape hesitated, thinking before responding to the boy's observation. "I imagine you were more likely to recognize it because of our... Occlumency... lessons..." he ended on a sardonic note.

"Maybe," Potter mused, though he sounded uncertain.

"It's not usually a skill one finds in someone your age. In fact, it's quite a rare skill altogether. Few witches or wizards acquire it, or learn to read another's signature unless they are bonded."