By the time Lan Wangji finds a cave deep enough, on a mountain secluded enough, that he feels it's safe to stop, the sun has long since set. The air that resists his passage on Bichen has grown thin. His face is no longer flecked by occasional raindrops, but hit by sharp-edged ice crystals; nonetheless, the bundle in his arms has stopped shivering. When he realised that, his heart plunged so hard he thought briefly that he was actually falling from the sword.

He pushes through the cave's chambers bent over his burden, Bichen sheathing itself almost without a thought from him. Deep at the back, the ground is dry though cold. Lan Wangji lays Wei Wuxian down on the bare rock and lights a fire talisman. There is nothing here to build a campfire with. Later, he'll have to gather up last autumn's dead leaves from further out in the cave, but he can't leave him alone yet. In the flickering, short-lived light from the talisman, he examines Wei Wuxian's slack face and holds his fingers up to his nose, making sure he's still breathing. Then he opens his own outer robes and pulls the other cultivator towards the only available source of warmth: his own body.

He listens to the wind in the trees outside the cave, the sounds filtered strangely by the rock chambers in between. Even he doesn't know where they are, thanks to his efforts to shake off any cultivators who might have followed them from the carnage in Nightless City, but he still expects to be discovered at any moment. He can't risk another fire talisman. The reassuring glow of Bichen's blade, even an inch unsheathed, is out of the question. Lan Wangji sits in the dark, supporting Wei Wuxian's dead weight, ready to defend them both.

The first night passes that way, and much of the first day. Wei Wuxian begins to shiver again, and later to shudder, his limbs jerking like a man trying to stop himself from falling, but his eyes don't open. Lan Wangji passes spiritual energy to him. At one point in the night, he finds his arms trembling and realises that he is holding Wei Wuxian too tightly, clinging to him more to get comfort than to dispense it. With an effort, he loosens his grip.

He makes calculations—who is left alive to pursue them, who knows what, which avenues are still left for them to run down—forcing his mind to stay rigidly in the future, because if it drifts towards the past he will see Nightless City again. He will find himself looking into the greying faces of Lan disciples he had grown up with, now with blank eyes and jaws twisted open, bellowing incoherently. One of his shidis' chests was ripped open with five parallel, bleeding gouges. Another had a dark hole for an eye, and a flap of his cheek hanging wetly down over the rest of his face, swinging as he moved. Others were merely slashed open at the neck or pierced with arrows whose shafts caught on the robes of cultivators they attacked. They were uncoordinated, disoriented; their sword strokes held to no official patterns, which only made them harder to predict. All that the cultivators of the Four Clans could do was fight back, but each one of their attacks only strengthened the forces of the Yiling Patriarch.

After an hour, Lan Wangji was the only one who still fought to gain ground, to get closer to their sole living enemy. Everyone else, the disciples who had been so keen on the demonic cultivator's destruction, was now desperate only to survive or to escape. Clawing his way deeper into the thicket of puppeted corpses stroke by stroke of Bichen, sending out chords from his guqin whenever he could make the space to do so, he had almost forgotten that there were living men and women on the battlefield. His boots slipped on soft matter that he did not dare to identify. He felt like a beetle in an anthive, being pulled inevitably down by a mass of weaker opponents.

Over everything floated the nagging, unnatural tones of Chenqing—and occasionally, worse even than that, laughter.

Lan Wangji blinks. Twice. He wrests his mind ungently towards the future.

When the dim glow of daylight from outside has reached its brightest and started to recede again, Wei Wuxian's head rolls to the side, away from Lan Wangji's chest. His eyelashes flutter on the sallow cheeks and his lips close and part again, the lower lip sticking briefly to the upper one before peeling away. He looks, for less than a heartbeat, like a little boy waking from sleep.

Then he squints up at Lan Wangji's face, his mouth distorts and he says, "You."

Lan Wangji nods.

Wei Wuxian twists away, struggling out of his arms to spill in an ungainly pile on the rock floor. There is a rattle as something hard, perhaps his flute, falls from his sleeve and rolls away into the shadows. His feet are tangled in the layers of ragged black robes and his head droops under its own weight. Eventually, he speaks again, directing his words to the dust and grit beneath him. "Lan Zhan. Get lost."

Lan Wangji waits until he has stopped moving before rising to his own knees and aiding Wei Wuxian to sit back, against the cave wall. He holds the other man's chin and tilts his face upwards to examine it. He extricates one filthy hand from within a mass of red and black sleeves and feels for the pulse in the wrist. "You need to rest," he says.

He doesn't venture far from the cave, that afternoon. By good fortune, there is a mountain stream that runs down from above their position, the water clinging to the vines that half-cover the cave mouth and carrying on along a narrow gulley between the trees. He pulls an empty gourd from his sleeve and fills it, drains it into his own mouth and refills it for Wei Wuxian. They are many miles from Gusu but the plants that grow here are familiar. When he dares to take more time away, he will dig up edible roots and search for berries that might have started ripening early. For now, he pulls off strips of bark that he knows has medicinal powers and plucks green herbs from the grainy soil nearby. Wei Wuxian will have tea to drink, at least, and he must clean him up in order to find any injuries hidden beneath the grime.

If Wei Wuxian doesn't cooperate with this process, he at least doesn't really resist. He lies bonelessly as Lan Wangji wipes at his skin with a soaked pad torn from his own robes, the white cloth coming away brown and black and red impossibly many times. The dirt clings in particular to his hands, where it blackens his fingernails and is ground into the lines of his knuckles and even the grain of his skin. It's as if he has been digging with his bare hands—digging in grave dirt—ever since Lan Wangji last saw him.

His hair is tangled, stiff and dull, not the glossy strands Lan Wangji remembers flying out as a slender boy ran through the Cloud Recesses, breaking six Lan principles at once for the joy of it. He pulls it back into a ribbon so that at least it's out of Wei Wuxian's face.

Apart from superficial cuts and bruises, he finds no real damage from the battle on Wei Wuxian's body. The only truly worrying signs are older: thin patches of skin on his arms and lower legs, shadows around his too-prominent collar bones and elbows, as if his flesh were slowly giving up on rebuilding itself. Lan Wangji's fingers hover over the long-healed Wen brand on his chest, an unreadable pattern of rippled pink. Does it still hurt, after so long? When Wei Wuxian makes a grumbling noise in his throat, he yanks his hand away, pulls the undershirt back into place and starts drawing his robes back together, one at a time. It's a ridiculous number of layers, even after the unrescuable outer coat has been discarded, but at least it will keep him warm. At least it will save Lan Wangji from having to see how thin he is.

He allows himself a short time, while the sky behind the trees is still softly alight, to wash in the stream and run through sword forms. His aching limbs need to move if he is to stay ready. Bichen's weight in his hand is a promise to himself that he will win the battles to come.

Wei Wuxian is silent and indifferent to his presence. He accepts a bowl of tea, which is to say he lets Lan Wangji place it in his hands and then seemingly forgets all about it until the liquid is cold, at which point he swallows half of it in an absent-minded gulp. Lan Wangji has been waiting for his complaint about its bitterness. It doesn't come; his lip barely curls. A few minutes later, the bowl slips out of Wei Wuxian's grasp as he tries to roll onto his side, and cracks in two.

In the back of his mind, Lan Wangji tallies the contents of his qiankun sleeves and how many things they can afford for Wei Wuxian to break. He pours the last of the tea into his own bowl and sets it between them.

Wei Wuxian falls asleep next to the fire, on the thin cushion of cloth and leaves that Lan Wangji has scraped together for him. One moment he is awake, sullenly staring into the flames, and the next he is snoring, a scowl still on his face, as though he hadn't wanted to fall asleep but accepted it as the marginally better choice over being here with Lan Wangji.

For a short while, the atmosphere in the cave is lighter. It turns out, though, that Wei Wuxian asleep is more talkative than Wei Wuxian awake and exhausted from battle. Before long, he is rolling from side to side, kicking feebly at the white outer robe draped over his lower body. Lowering his ear to the chapped lips, Lan Wangji hears his repeated hoarse calls for his shijie. Other names surface at intervals: Wen Qing (to whom he pleads not to be stuck with any more needles), his shidi Jiang Cheng, A-Yuan, a Fourth Uncle and a Sixth Uncle. Did Jiang Fengmian or Madame Yu have brothers? The question is half a minute's welcome distraction.

He has to walk to the cave's entrance to listen out for any approaching pursuit. The last time he returns to take his seat against the rock wall, the sleeping man is silent again and he feels a brief signal-flare of panic. Before he knows it, he has grabbed Wei Wuxian again, his fingers pressing against the pulse beneath the tense jaw. Wei Wuxian's skin is hot and his spiritual energy is almost indiscernable. Without letting him go, moving by touch alone, Lan Wangji pours cold water on a cloth and holds it to his forehead.

His own name is never called until the deepest hours of the night, when Lan Wangji has permitted himself to fall into a brief meditation, to preserve his strength. Even a whisper would pull him out of it. When Wei Wuxian jerks double in his arms and wails, "Lan Zhan!" he is immediately alert.

"I am here," he says softly.

"Lan Zhan! Lan Zhan!" Wei Wuxian cries. His eyes are open but unfocused. Sweat stands out on his brow, the droplets rolling into his fine black eyebrows.

"Wei Ying, I am here," he repeats, but Wei Wuxian doesn't seem able to hear him. He keeps calling out the name until his voice cracks into sobs that shake him painfully against Lan Wangji's chest, and at last he cries himself back to sleep.