"Good night, Professor." Snape inclined his head slightly, preparing to turn and leave.
Just then, he felt a faint movement at his collar. Nagini's slender body slipped out from beneath his robe collar, her forked tongue flickering lightly in the air.
Snape's hand shot toward his neck, trying to push her back in, but it was too late, Dumbledore had already seen her.
When those green, slit-pupiled eyes met the blue ones behind half-moon spectacles, Dumbledore seemed to show a flicker of surprise.
"Severus," Dumbledore's voice was still calm, but Snape caught a subtle ripple in its tone, "it's been a while. Don't rush off yet, let's go to my office and have a little talk."
Nagini had already slithered back into his clothing.
"Follow me." Without waiting for Snape's reply, Dumbledore turned and began ascending the stairs.
On the eighth-floor corridor of the castle, Nagini twisted uneasily inside Snape's sleeve, her scales scraping against the inside of his wrist.
"It's fine. Be still," he hissed softly in Parseltongue, a sound only snakes could understand. "He won't hurt you."
Ahead of him, Dumbledore's footsteps paused for a fraction of a second before continuing upward.
"I suppose this isn't the ordinary sort of pet relationship, is it?" Dumbledore's voice drifted down from above.
"Cockroach Cluster," Dumbledore said to the stone gargoyle.
As the gargoyle leapt aside, revealing the spiral staircase, he turned to Snape and asked, "Severus, when did you first master Parseltongue?"
"I'm not entirely sure when," Snape said as the staircase began to rise. He chose his words carefully. "Perhaps it was from the moment I conjured a fully formed Patronus..."
"Though, when we entered Bob Ogden's memory, I was surprised to realize I could understand Parseltongue." He paused briefly before deciding to speak the truth. "Please forgive my discretion, Professor, as you know, Parseltongue is often associated with Dark Wizards, so I chose to keep it secret."
"Fascinating. Truly fascinating, Severus." Dumbledore stroked his long beard thoughtfully. "Parseltongue is typically inherited by bloodline; it's extraordinarily difficult, nearly impossible, to learn after birth."
"However," he added, glancing meaningfully at Snape, "I have also never met anyone with a serpent-shaped Patronus."
"Well..." he said. "It's not all that important. Come in."
Dumbledore gently pushed open the office door. Fawkes opened his eyes upon the perch, his golden-red feathers gleaming brilliantly.
They entered the Headmaster's office. Dumbledore went around behind his desk and sat, gesturing for Snape to take the high-backed chair opposite.
As soon as Snape sat down, Nagini eagerly slipped from his sleeve, gliding along his arm and onto the Headmaster's desk.
A clear, piercing cry split the air.
Fawkes dove from his perch, fiery red tail feathers trailing in a blazing arc.
Nagini instantly coiled, her neck expanding into a defensive hood as she hissed sharply.
"Fawkes!" Dumbledore barked, halting the phoenix.
At the same moment, Snape stood, turning to shield Nagini with his own body.
Dumbledore waved his hand, and a streak of silver light guided Fawkes back to his perch.
The phoenix banked sharply midair and returned, though its golden eyes remained fixed on the little snake on the desk.
"It seems our friends don't quite get along, Severus," Dumbledore said evenly, though his gaze grew sharper. "Where did you meet this snake? Albania? Could it be that you are the Parselmouth mentioned by Bertha Jorkins in The Daily Prophet?"
"Yes, in the forests of Albania," Snape replied softly. "Quite surprising, I hadn't expected Bertha to be so principled as to refrain from naming me directly. Professor, she has a name, Nagini."
"How did you know her name?" Dumbledore's fingertips tapped lightly against the desk.
"It was obvious, Professor," Snape said, meeting Dumbledore's eyes. "She told me herself." He paused deliberately. "You... know her?"
The room fell silent for a moment, broken only by the faint snores from the portraits of past Headmasters and the occasional disgruntled trill from Fawkes.
"Yes," Dumbledore finally said. "You might say she's an old acquaintance of mine." His gaze settled on Nagini, coiled beside Snape's hand. "Severus, could I trouble you to help me speak with her?"
Dumbledore's request made Snape raise an eyebrow. He blinked. "You're not a Parselmouth yourself?"
"I can understand, but I cannot speak, nor can I influence serpents," Dumbledore admitted with a smile. "Rather like reading a foreign language without knowing how to speak it."
"I see." Snape nodded. "But I can't guarantee the conversation will go smoothly. Her linguistic ability seems rather limited, she can only express a few simple words. What do you wish to ask her, Professor?"
"Ask her," said Dumbledore, "what she's been through all these years."
Snape leaned forward, looking at Nagini, and hissed softly, "Nagini, this is Professor Dumbledore. He wants to talk to you, he wishes to know what you've experienced over the years."
The little snake lifted her head, tongue flicking rapidly, and uttered several fragmented, indistinct sounds.
"Cre... den..."
At first, the broken syllables made no sense to Snape. After several attempts, he finally pieced together her meaning, she was not answering the question at all, but struggling to pronounce a name: Credence.
Snape straightened and saw Dumbledore's fingers tighten slightly on the desktop.
"Credence?" Snape feigned confusion. "Who is that?"
Dumbledore's hand froze midair.
"An... old friend," he said quietly, his gaze drifting past Snape, into empty space behind him.
"Old friend? What do you mean?" Snape pressed. "What happened to him?"
The Fantastic Beasts series had never received a complete conclusion; after The Secrets of Dumbledore underperformed, Warner Bros. abandoned the follow-ups. Thus, Snape, too, knew nothing of what became of that story.
"He's gone," Dumbledore said, fingertips steepled together.
Both men looked down at Nagini. Her emerald eyes gleamed in the candlelight, filled with something almost human, a kind of yearning.
"How should I tell her?" Snape asked, glancing at Dumbledore and then at Nagini, his voice soft with pity. "Should I tell her that Credence has gone?"
"To dwell in false hope while forgetting reality," Dumbledore said gently, "is the cruelest form of torment, Severus." He nodded.
Snape did not translate immediately. Instead, he asked again, "What did Credence mean to her?"
"They were... friends," Dumbledore said softly. The word carried unusual weight from his lips. "Two cursed souls who found warmth in one another during the darkest of days."
Snape turned toward Nagini. After a moment's hesitation, he began to hiss again.
Nagini's body stiffened, then sprang outward like a coiled spring.
Her scales burst with dazzling light, her body expanding rapidly as the Shrinking Charm shattered like paper.
A twelve-foot serpent now coiled in the center of the Headmaster's office, her eyes blazing with pain and fury.
Silver instruments spun and hissed, spilling smoke as her massive body knocked them from the oak desk. Ink from a fallen bottle spread in dark blue pools across the wood.
Almost instantly, Fawkes spread his wings again, soaring to confront Nagini, golden fire streaming from his beak.
Dumbledore sprang up, and Snape already stood before Nagini, his black robe singed by the phoenix's sparks.
"Fawkes, back!" Dumbledore raised his arms, conjuring a transparent barrier before the desk.
The phoenix chirped in confusion but obeyed, circling back to its perch.
"Nagini," Snape said, without turning, locking eyes with her. "Stop-"
Before he finished, Nagini had already calmed.
The violent thrashing ceased. In her eyes, Snape's figure was reflected.
Her great head drooped, fury melting into grief. In those eyes, Snape saw sorrow, and apology.
Nagini lowered her head, gently brushing Snape's cheek. Her cold scales pressed against his skin.
"All right," Snape murmured, stroking her neck and feeling her trembling faintly. "I'll shrink you again."
With a tap of his wand, the Shrinking Charm took effect once more, and Nagini returned to her small form, coiling upon the desk.
Dumbledore waved his wand, setting toppled objects back in place.
The office returned to its prior order, as if nothing had happened.
"Professor," Snape said, resting his hand beside Nagini so she could lay her head upon it, "what exactly happened between Nagini and Credence?"
"Nagini was a Maledictus," Dumbledore said after a pause. "She came from Indonesia. And Credence... was a soul burdened by an Obscurus."
"I know what an Obscurus is," Snape replied. "But a Maledictus, that means she was once... human?"
"Yes," Dumbledore sighed deeply. "Blood curses are unique kinds of maledictions. They do not kill directly but are hereditary afflictions. A Maledictus carries such a curse, eventually, they transform permanently into beasts."
"Then can she ever turn back into a human?" Snape leaned forward.
"To my knowledge, no." Dumbledore's concise answer carried quiet cruelty. "Once a Maledictus fully succumbs, the change cannot be reversed."
"I see." Snape glanced at Nagini. "I used to think only the Killing Curse was irreversible. Please, Professor, continue her story."
"They met when both were lost, and parted when faced with choice," Dumbledore said, eyes drifting toward the bright night sky beyond the window. "In 1927, they met in Paris, two outcasts shunned by the world. Later, in the struggle against... a Dark Wizard, they stood on opposite sides. Perhaps Nagini still wished to save her friend then."
"She chose her path, and he chose his." Snape took a deep breath. "'Choice', such a beautiful word.
"Our choices are as defining as our abilities. I choose to stand with you, Professor, even if I speak Parseltongue."
A smile returned to Dumbledore's face.
"However," Snape continued, "it sounds like there was another major figure in that story, a Dark Wizard before Tom. That was Gellert Grindelwald, wasn't it?
"How did you defeat him? What really happened between you and Grindelwald?"
"That is a much longer tale, Severus." The smile faded from Dumbledore's face.
"It's very late, you should rest." He rose, gesturing toward the door. "Being late on the first day of term would set a poor example for the Head Boy. If you're tardy to tomorrow's Defence Against the Dark Arts lesson, I may have to reconsider your position."
"Of course, Professor." Snape bit back the words old fox, letting them die in his throat as he guided Nagini back into his robes.
As he turned to leave, he caught sight of Dumbledore standing by the window, moonlight pouring over him, making him look like a marble statue.
After leaving the Headmaster's office, Snape didn't return directly to his dormitory. Instead, he stopped before the Room of Requirement.
"Well, I can't let you stay cramped like this forever," he murmured, feeling Nagini's gentle coils beneath his sleeve. "I envy Newt Scamander's suitcase, wonder how he built it."
He paced before the white wall three times, and a wooden door appeared, leading to "a place suitable for serpents."
Opening it gently, he found a small grove within: several tall dead trees, winding vines, and a little pool. Yet there was no scent of forest, no sound of life, only an empty imitation.
"This..." Snape hesitated, calling out Nagini. "What do you think of this place?"
Nagini peeked out, gave one glance, and immediately withdrew. Snape understood her meaning at once.
So, the Room of Requirement wasn't an omnipotent wish-maker after all; it couldn't recreate a living ecosystem.
With a sigh, Snape carried Nagini back to the Slytherin dormitory beneath the lake.
When he changed out of his robes and into his nightclothes, Nagini crawled up again from the floor, winding her way back onto his shoulder.
Fortunately, Eber had already drawn the bed curtains and fallen asleep.
"Nagini," Snape murmured amid the faint sounds of lake water, running his fingers along her smooth scales, "rest now. And remember, no biting. I'll find a better place for you soon."