Based on the poem "A Ballad: The Lake of the Dismal Swamp" by Thomas Moore:
"They made her a grave, too cold and damp
For a soul so warm and true;
And she's gone to the Lake of the Dismal Swamp,
Where, all night long, by a fire-fly lamp,
She paddles her white canoe.
"And her fire-fly lamp I soon shall see,
And her paddle I soon shall hear;
Long and loving our life shall be,
And I'll hide the maid in a cypress tree,
When the footstep of death is near."
Away to the Dismal Swamp he speeds—
His path was rugged and sore,
Through tangled juniper, beds of reeds,
Through many a fen where the serpent feeds,
And man never trod before.
And when on the earth he sunk to sleep,
If slumber his eyelids knew,
He lay where the deadly vine doth weep
Its venomous tear and nightly steep
The flesh with blistering dew!
And near him the she-wolf stirr'd the brake,
And the copper-snake breath'd in his ear,
Till he starting cried, from his dream awake,
"Oh! when shall I see the dusky Lake,
And the white canoe of my dear?"
He saw the Lake, and a meteor bright
Quick over its surface play'd—
"Welcome," he said, "my dear one's light!"
And the dim shore echoed for many a night
The name of the death-cold maid.
Till he hollow'd a boat of the birchen bark,
Which carried him off from shore;
Far, far he follow'd the meteor spark,
The wind was high and the clouds were dark,
And the boat return'd no more.
But oft, from the Indian hunter's camp,
This lover and maid so true
Are seen at the hour of midnight damp
To cross the Lake by a fire-fly lamp,
And paddle their white canoe!
He knows immediately that something is wrong.
He's back in the body he had when he was in his 20's — the click in his hip is missing, the limp that accompanies it long gone. Soft dark hair falls to the middle of his back, the permanent ache that normally resides in his vertebrae reduced to a shadow of what it normally is. It's dark; just light enough that he can see the faint outlines of endless trees. The air swirls around him in a thick mist, smelling of decay and rot and damp earth. A much-too-large full moon hangs in the sky, it's white light ominously poking through the treetops at random intervals.
He starts walking.
The ground shifts beneath his bare feet, wet and muddy, and worms and bugs crawl over his skin, crushing under his heel. Water rises to his ankles, blisteringly cold and thick with muck. It smells like bile and death. The soupy air parts around him like a veil; he almost has to push his way through it with his freezing hands. A cold sweat sticks to his every inch, sucks his shirt to him like a second skin. The texture drives him mad, makes him itchier than the invisible insects creeping up his shins.
A lone cypress tree is bathed in moonlight, a living lighthouse in the dark swamp around him, and his feet carry him soundlessly to it. Its roots protrude from the ground, gnarled fingers breaching the earth, waiting for something to grasp and reclaim. As he approaches, ignoring the slithering chill that drips down his spine, the moon highlights a dark lake beyond the cypress' trunk. The water shines obsidian in the night, black glass against the charcoal backdrop of the swamp. A spotlight forms in the bright rays, and lands on a woman in a white canoe. Her pale clothes drip from head to toe; the milky color stands out against the dark backdrop. A wide brimmed hat drapes a tattered chalky veil over her face and hair, but Zuko knows immediately who it is.
Katara.
His lips don't move around the word, but the sound projects regardless. It carries through the air, a melancholy melody, steeped with longing and sorrow. Katara turns to him, sinuous and smooth. Her eyes aren't their normal vibrant blue; they reflect the moonlight like the lake upon which her white canoe sits, volcanic glass shards rounded to fit in the sockets of her eyes. The canoe glides across the water, silent, ripples absent in its wake. The only sound is the soft dip of a mangle white paddle that Katara uses to push herself along. She disappears behind the cypress tree. Zuko looks around its trunk and sees her back, the white canoe carrying her farther away faster than he can comprehend.
Before he can think, he's running after her. His heart pounds in his chest, the sound loud in his ears, mixing with a faintest whispers behind his back. He can feel the darkness catching up to him, it's fingers scrabbling at his shirt with each step, and somehow he just manages to pull away each time. But Katara's visage continues to elude him; it's like he isn't moving at all. Foliage brushes his bare legs, sticks and rocks jab into the soles of his feet, muddy water splashes under his footfalls as he runs.
His toes catch on a particularly thick branch, and his face falls straight into the mud. Dank earth enters his nose and mouth. Death sits on his tongue, weighing his head down. Snakes crawl over his legs and back; their smooth bellies leave stinging blisters trailing up his body. Bugs crawl into his ears, create a buzzing in his brain. Vines twist around his ankles and wrists, around his neck and head, and in an instant, he is sucked into the swamp floor.
Zuko bolts upright in bed, drenched in cold sweat, chest expanding and contracting rapidly around ragged breaths. It takes him a moment to come back to himself; the bed he's in is familiar, the hands he rises shake, but they are his own, wrinkled and tired with age. His head whips to his left in hopes that maybe, miraculously—
The pillow next to him is empty, as it always is.
He cradles his head in his hands. Mostly grey hair slips over his shoulders to curtain his face and hide his tears. Will he ever stop looking for her upon his waking? Katara's been gone for thirty years. She isn't coming back.
The floor is chilled beneath his feet when he rises from the bed. A deep blue robe is draped around his shoulders: it's much too small, and barely fits around his back, but he wears it nonetheless.
His feet tread a familiar path to the front porch of their modest house. After he had abdicated his throne to their firstborn, Zuko had moved to a quiet Earth Kingdom town on the sea, somewhere almost equidistant from her home in the South Pole and his in Caldera. He visits the South Pole often, taking comfort in Sokka and Suki's presence. But tonight his thoughts are not in the South Pole, nor Caldera, nor their house by the shore. They are tangled in the vines of a thick swamp, plagued by the vision of his late wife gliding through dark water in a white canoe.
A shooting star flies above his head towards the sea.
Gravel crunches under his bare feet as he moves, making his way to the shore in the dark of night. He doesn't bother lighting a flame in his palm; the full moon gives him enough light to follow the short path to the beach.
His mind is quiet, silent, actually, as the sand squishes and parts beneath his heels. As it gets more saturated with salt water, it stiffens, before becoming soft again as he steps into the water. To his left sits a white canoe, a spitting image of the one Katara had piloted in his dream. He's never seen it before tonight, but the thought barely registers over the sound of crashing waves.
In a blink he's picking up the single oar and paddling the canoe out into the sea, following the trail of the shooting star that had passed right over his head. Why am I doing this? He doesn't usually feel compelled to canoe at night… or at all, for that matter. Walking down to the beach had been almost expected— he spends many nights with his feet in the sand, bathed in the glow of the full moon. Where am I going? The shooting star shines in his mind's eye, so bright that he can almost see it in the sky.
The muscles in his arms burn; he has no idea how much time has passed. The night is still dark, but the shore is far behind him. I have to turn around. His limbs are not under his control. They are compelled by some alien force, pulled by heavenly strings tied to the fingers of an otherworldly puppeteer. No matter how hard he tries to fight it, the oar continues to dip into the water and propel him forward. I'll die out here. The thought does nothing to stop his journey. His knuckles are white under the strain of his grip on the oar. The water is black glass beneath him, silent despite the gentle waves. Golden eyes dart around, frantic for an answer that he knows, deep down, that he will not find. The only thing he sees, other than the moon and the waves, is the faint image of a woman in white carrying a lamp off in the distance.