A black-sailed boat heaved and dipped beneath howling winds as it carved a path across the sea, bearing Snape and his companions toward Azkaban.
They stood on the narrow deck, cold, salty spray lashing their cloaks, stinging their faces like tiny knives.
With a flick of his wand, Dumbledore conjured a shimmering dome overhead, shielding them from the worst of the sea's fury.
As they sailed onward, the sky gradually darkened, as though a vast curtain of shadow were falling across the heavens. The air turned unnaturally cold, and thick fog crept in from every direction, curling around them like ghostly fingers.
Even with their travelling cloaks drawn tight, the chill seeped into their bones. A formless dread unfurled within, worming its way into the corners of their minds.
Snape's limbs began to tremble. Long-buried memories—moments of guilt, loss, and humiliation—rose unbidden, whispering their poison in his ears.
Before Dumbledore could react, Snape raised his wand with a sharp breath. "Expecto Patronum!"
From the tip of his wand burst a silver serpent, gleaming bright as moonlight.
This time, it was no flickering mist. The Patronus shimmered with intricate patterns along its length, solid and proud, its sinuous body coiling protectively around Snape, hissing softly.
"Oh, so it's a snake," Snape muttered under his breath. "For a second I thought you might sprout antlers and eagle talons."
The suffocating dread receded within the Patronus's light. Warmth and clarity returned. Hope flickered back into their chests like a rekindled flame.
"You've conjured a fully-formed Patronus, Severus," Dumbledore said, eyeing the snake with a mixture of approval and amusement. "That puts me at ease. Even if... it's a snake."
"What's wrong with snakes?" Snape gently stroked the creature's head. "They can be quite charming."
The boat rocked harder as they ventured deeper into open water, and the sea darkened like ink.
A jagged bolt of lightning split the sky, and heavy raindrops pelted the surface of the waves.
For a fleeting moment, the lightning illuminated the shadows, revealing dark shapes gliding above the water—Dementors, drifting like vultures. The air grew colder still, thick with their despair.
Eventually, through the storm and sea mist, the prison emerged—Azkaban, the fortress whose name meant ruin, abyss, and worse.
It loomed like some ancient leviathan risen from the deep. Rain lashed its rough, glistening stone walls as the boat scraped up to the shore.
Under howling wind and slanting rain, the three men clambered onto the rocky bank.
"Tell me," Snape asked once he'd caught his footing, "do you suppose a scrawny mutt could swim all the way from here back to the Highlands?"
"What a curious question," Dumbledore murmured, casting several protective spells with a wave of his wand. "Even a three-headed magical hound would have little hope of swimming from here to land."
"No reason," Snape replied. But inside, he couldn't help admiring Sirius. After twelve years of incarceration, what must it have taken to cross the North Sea and reach Hogwarts?
"Shouldn't the Ministry have someone stationed here?" he asked, staring at the bleak towers and empty gate.
"You'd place a lowly Ministry official here for days on end, Severus?" growled Moody, thumping his cane against the rock. "Let's move."
They stepped into Azkaban.
Inside, it was no better. The air hung heavy with damp rot. Water dripped continuously from the ceilings. Torches lining the walls burned with a sickly green glow, offering no warmth.
Most of the prisoners lay motionless in their cells, barely breathing, unmoving. Only the faintest rise and fall of their chests proved they were still alive.
A few murmured to themselves in the corners of their cells, hollow-eyed and lost in their minds.
As they passed one particular cell, Snape halted abruptly, then doubled back.
"What is it?" Moody asked quietly, one eye twitching.
"I know him," Snape said, frowning.
Inside sat Mulciber, a fellow Slytherin from years ago.
Mulciber stirred at the noise, his vacant eyes scanning the corridor beyond the bars. His cracked lips moved without sound: Help… help me…
He hadn't been there long—his mind hadn't yet surrendered completely.
"Let's keep moving," Snape said. "I used to tell everyone who asked for help 'sure, sure'—then never followed through.
"It's not a good habit. Now, unless I genuinely want to help, I just say no and walk away.
"Bit of self-training. For sincerity. And courage."
"Severus," Dumbledore leaned in and whispered, "do teach me that silencing charm of yours. I find myself in sudden need."
"I'll shut up, Professor." Snape mimed zipping his lips shut.
Just then, a blind Dementor floated past, drifting toward them like smoke, drawn to the rare scent of happiness.
Before Snape could command it, his Patronus struck.
The silver snake darted forward, coiling around the Dementor like a vice.
Black mist hissed from the creature's form. It gave no cry, but the agony on its faceless form was unmistakable.
Moments later, all that remained was a torn, filthy cloak on the floor. The Dementor was gone.
"Professor," Snape turned, wide-eyed. "I thought Dementors couldn't be destroyed?"
"I suspect," Dumbledore murmured, voice low, "your Patronus carries something… extraordinary. Like sunlight at dawn."
"Well, you must be the sunset, then." Snape rolled his eyes, scooping up the cloak with a sigh and pressing forward.
"There she is," he said at last, pointing to a shriveled, aged house-elf curled in a corner cell. "I believe that's Hokey."