Nymeria Sand
Lady Nym, second of the Sand Snakes: elegant, cool, and lethal, favoring the whip and a hidden blade.
A soul of House Martell, born at Dorne.
The fuller tale
Season One
At the Crossroads, Joffrey's cruelty leaves the butcher's boy dead, Nymeria banished, and Lady executed in her place.
Season Seven
Arya turns north at the crossroads — Winterfell, not King's Landing — and meets Nymeria's pack in the wood.
Their story
Nymeria — Lady Nym, and the courtesy title is only half irony — is the second of the Sand Snakes and the proof of how differently Oberyn's daughters were made: her mother was a noblewoman of old Volantis, and Nym was raised to silks, courts and patience as surely as Obara was raised to the spear. She is the sisters' elegance and their arithmetic — beautiful, unhurried, amused — and the books give her killing style to match: not the open duel but the hidden edge, a dozen blades about her person and the flexibility to have any of them arrive first. Her petition to Doran after her father's death is characteristically exact: not war, just four deaths, matched and named, a debt settled at par.
Doran's answer is the books' best joke about her: he grants Lady Nym precisely the weapon she is — a seat, sending her to King's Landing to fill Dorne's chair on the small council, a serpent posted to the capital with letters of credence. The published books leave her en route to that appointment, the realm's most dangerous councilwoman not yet seated. The show pares the elegance to a whip and a smirk and enlists her in the coup — vengeance by family vote rather than the books' cool itemized invoice.
How it ends for them
On the screen. Slain at sea (S7·E2)
The whip-wielding Sand Snake fought Euron Greyjoy across a burning deck and lost. He strangled her with her own whip and displayed her beside her sister — a message to Dorne.
The show ends her beside her sister, in the same burning night. When Euron Greyjoy's ambush shatters Yara's fleet in the narrow sea, Nymeria fights him across the deck and loses, and Euron — a connoisseur of the personalized cruelty — strangles her with her own whip and hangs her from the prow beside Obara, the Sand Snakes' bodies rigged as the figureheads of Dorne's failed war. Ellaria and Tyene, taken alive in the same action, are sailed to King's Landing as gifts for Cersei; Dorne's part in Daenerys's grand coalition ends in one engagement. In the published books Nymeria Sand is alive and travelling toward the small council in King's Landing, blades distributed, invitation genuine, outcome unwritten.
Their chapters, book by book
A Game of Thrones 2 chapters that name them
A Storm of Swords 1 chapter that name them
Where the page and the screen part
Book Nym's whole trajectory — the four-names petition, the council seat, the journey to a capital that has no idea what Dorne has just mailed it — is unplayed in the show, which kept her name, her whip and little else. The show's Nymeria helps murder Trystane, a cousin her book self is busy avenging house Martell for, not against; the inversion is the same one that swallowed Ellaria, applied a generation down. Her weapon also migrated: the books' Nym is a knife artist, and the whip the show made her signature belongs, in the books, hanging on her sister Obara's saddle.
Their journey
Where the two tellings send them to the same place the road runs whole; where they part, the screen keeps the left and the books the right.