First, let us explain our "we."
We were a pair of mandarin ducks on Mirror-Shadow Lake, two generations before old brother Mandarin. We never lost each other — we grew old together. In the winter of our last year, with the lake sealed under ice, we twined our necks together for warmth and slept.
When we woke, the ice had melted and we had become a spirit — one spirit. Two ducks, one body, two heartbeats, one name: the Paired Mandarins.
It was awkward at first. He wanted east, I wanted west; one set of wings beat in two directions, and we crashed into the reed-beds seven times. It took a dozen years to learn: twining necks does not mean one obeys the other. It means learning to negotiate two wants into one going.
Three hundred years of negotiating later, we have negotiated ourselves a trade: thread-pulling.
The humans call the Old Man Under the Moon the thread-puller. His shrine has shown no sign in three hundred years — so we, a pair of amateurs, picked the trade up. We dare not claim his title. We do exactly one thing: find the separated, and bring them back together.
Couples scattered by war. Children stolen and sold. Parents and brothers fallen silent — in Western Liang and beyond, whoever has lost someone burns a seeking-letter at the lakeshore, and we take the commission.
By what power do we find them? We can see the red threads.
The Old Man's red threads are no fable. The bonds between people truly form threads: the couple's thread red and thick; mother and child's red and tough; friendship's paler; debts of kindness shot with gold. And threads do not break — however far apart the two ends walk, the thread only lengthens, thins to a hair, and holds.
Finding someone is simply lifting the seeker's end of the thread — and flying along it.
Three hundred years: four hundred pairs and more brought back together. Our farthest commission ran from Western Liang to the shore of the East Sea, the thread fine as spider-silk and unbroken the whole way — at its far end an old soldier who had kept a lamp burning for his sister forty years.
Around our second century, the trade taught us something worth more than any reunion: the thread has two ends. While you search for him, his end is pulling you. Any separation under heaven, so long as both ends still hold each other in mind, keeps its thread alive — and a living thread can always be followed home.
Only one kind cannot: when one end has forgotten first.
So the commissions we dread are the single-ended threads — the line runs out from the client's hand, pales along the way, and arrives grey. The person at a grey end usually still lives; they simply no longer remember. We take those commissions too — but from them we can bring back only a person, never a heart.
In three hundred years, grey-thread commissions: seven in all.
In these last three years: thirty-nine.
And of those thirty-nine, eleven were not grey —
they were severed.
The cut clean. As if by scissors.
Red threads do not break: that is our trade's iron law. While the holding-in-mind exists, the thread exists; when it fades, the thread pales or greys — it does not sever. What manner of thing can cut a thread? Only something that digs out the holding-in-mind by the root — not making him forget you, but expunging from the very ledger of heaven and earth the fact that a bond ever existed between you.
We traced the eleven severed threads to their far ends. The people there are all still "alive" — walking, eating, answering their names. Brother Wangliang took one look: every shadow, half a beat behind.
The replaced must have their red threads cut. Because the thing inside the shell holds no bond with anyone at all.
We delivered the register of the eleven severed to the westward company, and joined it ourselves.
On the road we practice our trade as ever: whoever in the company seeks someone, we pull the thread. Old brother Mandarin seeks his lady — we have looked at that thread of his. Red, and thick, and running west, bright as a small river. Fly easy, old brother.
As for our own private hope on this journey —
a thread-puller sees every thread under heaven except their own. That is the trade's rule, and heaven's arrangement.
But other pullers have told us: you two are lightly threaded to everyone — save that toward the west runs one thread older than old, worn white with age, one end tied at your twined necks —
and the other end tied at the hand of the last Old Man Under the Moon, before his shrine fell.
Three hundred years ago, he went west.
We are going to ask him: when you left, who was supposed to tie the world's red threads?
And — the scissors that are cutting them now: were they, once, an instrument of your shrine?