Seventy-six years after the Second Wizard's War, Mssr. Pince, a direct descendant of the great Madam Pince, saw a new entry appear in the Hogwarts Library catalog. It entered itself into the Restricted Section where, sure enough, the librarian later found a weathered leatherbound book that had no identifiable quality save for its previous owners, two faceless individuals: a Slytherin Prince, and a Crusader Queen.
Mssr. Pince rolled his eyes at the arrogance of the kids – for who else would self-style themselves in such a childish manner – who defiled the book by inking their ownership so boldly on the front page. However, it did not take long for the wizard to realize why the library had filed this book in the Restricted Section. He watched, mildly amazed, as a blood-curling spell wrote itself in sharp, angled letters on the very first page of the book. Obligated to report the appearance of dark magic material in the library, he made his way to the Headmaster's office and presented the book to Professor Scorpius Malfoy for perusal. To his astonishment (and subsequent embarrassment), no instructions for a dangerous spell appeared on the first page. Instead, a Muggle poem penned itself upon the crisp parchment.
Love is too young to know what conscience is,
Yet who knows not conscience is born of love?
Then, gentle cheater, urge not my amiss,
Lest guilty of my faults thy sweet self prove.
For, thou betraying me, I do betray
My nobler part to my gross body's treason;
My soul doth tell my body that he may
Triumph in love; flesh stays no farther reason,
But rising at thy name doth point out thee
As his triumphant prize; proud of this pride,
He is contented thy poor drudge to be,
To stand in thy affairs, fall by thy side.
No want of conscience hold it that I call
Her 'love' for whose dear love I rise and fall.
–William Shakespeare
"Professor, I swear—" Mssr. Pince began, but stopped at a gesture from the aged man lounging on his tall seat. Unceremoniously, the Headmaster closed the book, then opened it once more. Slowly, the two wizards observed yet another entry write itself upon the first page.
AGM: I miss you, my friend. Thank you for everything. I will never forget you.
The Headmaster inhaled deeply before closing the book one more time. "It appeared in the Restricted Section?" he asked, eyes lowered, unreadable.
"Yes, Professor. Would you prefer to keep it elsewhere? I can—"
"No, Mssr. Pince," Another deep breath, a small, almost invisible smile. "Thank you for bringing this to my attention, but I do not believe this book is dangerous enough to remove from the library. In fact.." He paused, the harsh lines of his face deepening slightly. "I believe this book is the only one of its kind. Take good care of it, will you?"
The slight confusion at the Headmaster's strange reaction had been forgotten by dinnertime. Mssr. Pince strode to the Great Hall, already dismissing the mysterious book that, from this day forward, would reside, obscured and almost-lost, in the countless bookshelves within Hogwarts Library's infamous Restricted Section.