Kreacher turned around fully and bore this comment with something approaching dark relish, scowling hard enough to curdle milk.
“What… key?” James asked with barely contained impatience.
Harry fished in the pocket of his robe and pulled out a simple key. It was made of some black metal, perhaps six inches long, ornately crafted with a ringed head, a long shaft, and complicated geometric teeth extending beneath. It was a handsome object, diminished only slightly by the layers of ancient tarnish and patches of rust that scuffed and darkened its surface.
“I found it in an iron lockbox beneath the bricks of the master hearth,” Harry said, cocking his head at his son. “It was about the hundredth place I looked. If it wasn’t for a handwritten clue I found in one of Sirius’ old record sleeves, I would likely be tearing this place apart to this very day. Once the calling comes, there’s no denying it. I expect you know that yourself, now.”
James took the key from his father, held it in his palm. Despite its tarnish and rust, its weight implied a very fine construction, heavy and solid. He looked back up at his father, his eyes narrowed.
“Years ago, when I asked you about this, you acted like you didn’t know anything.”
“And you will, too, should anyone ask you,” Harry replied soberly. “Although they won’t. Not even Merlinus knows this secret, though he may have his suspicions. Now go ahead.” He nodded toward the patiently waiting Kreacher.
James turned to the elf and, somewhat reluctantly, held out the key.
Carefully, almost reverently, Kreacher put out his huge hand, open, allowing James to place the key gently onto his palm. Kreacher closed his fingers over it slowly and turned away again.
“Apparently,” Harry said softly as Kreacher stepped toward the blank brick wall beyond the stove, “before this room was a lounge or a servant’s kitchen, back when it was first purchased by Slade Willibrord Black, it was outfitted as the antechamber to an ultra secret hidden chamber, long since forgotten. Pay attention to how Kreacher accesses it. He may not always be here to assist you.”
James watched as the old elf raised the key and held it approximately sixteen inches from the brick wall. He shifted it minutely, as if searching for some hidden quadrant of empty space. And then, strangely, metal clinked on metal. Decisively, Kreacher pushed the key forward, slotting it as if into an invisible keyhole. It chinked home, and the old elf gave the key a single, clockwise turn.
Purple light bloomed out from the key, fizzing as it went, first revealing a round metal panel and the hidden keyhole. The panel was as black as onyx, engraved with ornate scrollwork in the shape of an old English letter B. The sizzle of purple light expanded still, spreading side to side, up and down, revealing a complicated circular door made of the same black metal, studded with bolts and rivets, festooned with crawling scrollwork that picked out every feature, embraced every detail. When it fully resolved, the door stood like a round layer cake turned onto its side, ten feet tall, comprised entirely of black iron plates, ringed and bolted together, as heavy as a cathedral and twice as imposing. The key still jutted from the centre, slotted into its key-plate.
Kreacher bowed his head and stepped backwards, retreating into a far corner.
James was dumbfounded. He had been in the cellar room dozens, probably hundreds of times. Never had he suspected that it had any secret significance.
Tearing his eyes away from the huge Vault door, he asked his father, “Have you been in there?”
Harry gave a rather equivocating nod. “A few times. Three, in fact. Once to do the duty of our office. Twice… simply to see for myself, as you will now.”
James looked at his father. Harry met his eyes and gestured with his hand. An invitation.
James stepped toward the door. On the right side was mounted a thick metal handle, curved to conform to the door’s shape. James reached for it tentatively, touched it. He expected the black iron to be cold, but it was not. It was pleasantly warm, like the shade on a summer’s day. The metal thrummed a little, as if connected to some secret, far distant power source. The vibration of it carried up to his elbow. He swallowed nervously, and then gave the door a tentative tug.
The door unlatched, its bolts already unlocked by the key. It swung silently, slow and heavy on well-oiled hinges. The initial tug was all it took. Inertia swung the door in an irresistible ponderous arc, revealing a sort of shadowy cell beyond. The walls, floor, and ceiling of the space were seamless stone, as if the room was hewn from one gigantic, perfectly solid block of granite. The cell seemed perfectly empty and dark except for a single object in the centre of the floor. It was a sort of plinth or pedestal, constructed of the same ornately engraved black iron as the door, anchored to the floor with fist-sized bolts. Its base was wide and curled into baroque twists. Its body tapered upward like a tree trunk, flaring delicately toward a flat, pedestal surface.
A single, small object sat there, in a pool of mysterious golden light.
James stepped forward, up into the space. It was cool inside, cave-like, but not dank. The air was fresh somehow, mysteriously scented with running water and night-blooming flowers.
Upon the pedestal, a tiny book sat, open on its leather cover, its blank pages turned up to the light, as if waiting to be filled.
Harry moved close behind his son, unable not to look down at the strange little book and its blank, expectant pages.
“Merlin had a book like that,” James breathed, both awed and confused. “I saw him with it years ago. He was reading it on Hagrid’s ship. And on the morning after the Triple-Six enigma.”
“Merlin’s is a copy of a copy of a copy,” Harry said, his voice quiet and somber. The space seemed to inspire solemnity, not out of obligation, but out of a sort of innate, secretly giddy respect. James suddenly felt that he had to contain his emotions not because they were inappropriate, but because, if he gave them voice, he might laugh out loud with inexplicable joy, or break down into inconsolable tears, or draw his wand in search of a villain to best or a monster to slay. Here, in the presence of the Book, emotions were magnified into their purest, most visceral, gut-wrenching, and intoxicating selves.
Harry went on, keeping his voice low and steady, “This is the Book that all other books strive to be. It took me a little while to understand it myself. And even now, I grasp it only barely. Like a child grasps quantum technomancy.”
James tore his eyes from the creamy, golden, waiting pages, turned to his father, wanting to understand. Needing to understand.
Harry met his son’s eyes. “Every magical title is a custody of the elements of humanity. And each one is defined by their colour. You have observed this yourself. Greene is for ambition. Rose is for love.
Blue is for intellect. But Black… that one is different from them all.”