Grey Worm
Commander of the Unsullied, the elite eunuch soldiers of Astapor: disciplined past fear or feeling, slowly learning to be a man as well as a weapon.
A soul born at The Summer Isles, taken young, sworn to The Unsullied.
The fuller tale
Season Three
One of the Unsullied Daenerys buys wholesale from Kraznys mo Nakloz in Astapor, and among the first to step forward once she turns the army against its masters and offers every soldier in it a real choice for the first time in his life — walk away free, or stay and serve her freely. He stays, and keeps the name Grey Worm, a slave-name meant to shame him, because it was the name he was wearing the day he became a free man, which he decides makes it lucky rather than something to be rid of. Command of the Unsullied falls to him afterward, and it suits him.
Season Four
Settles into command of Daenerys's army properly now, methodical about sieges and garrisons, and spends what free hours he has learning letters and the Common Tongue from Missandei — careful, awkward lessons that seem to matter to him more than he lets on. Meereen is his to help hold once it falls, and it is a city that does not want holding.
Season Five
Ambushed in a Meereenese alley by the Sons of the Harpy alongside Ser Barristan Selmy — Barristan doesn't survive it, and Grey Worm is carried back near death, saved only because Missandei reaches him in time. Recovering, he tells her, more plainly than he has said anything to anyone in years, that what troubled him most about nearly dying wasn't missing the fight — it was coming close to dying without ever telling her how he felt. It's the most words he's spent on the subject in two years, and he means all of them.
Season Six
Back on his feet and back in the field, he and Tyrion out-think the masters' siege of Meereen while Daenerys is away, luring their fleet into the harbor and burning it rather than meeting it ship for ship. Boards the fleet bound for Westeros afterward, Missandei beside him, pointed at last toward a war he actually chose.
Season Seven
Leads the Unsullied against Casterly Rock exactly as planned and takes it in a morning — only to learn the Lannister army was never inside it, and the Rock was never really the point. Marches back east through a countryside that's turned hostile, and before it's done, finally lets himself and Missandei have the conversation they've been circling for years.
Season Eight
Survives the Battle of Winterfell and marches south with what's left of the army to finish the war properly — except the fleet is ambushed before it lands, and Missandei is taken and executed on the walls of King's Landing with him watching helplessly from the beach. What happens to the city once its bells ring surrender a few days later is not strategy anymore; Grey Worm leads it anyway, and does not look like a man interested in being talked out of it. Afterward he holds out for justice against the ones responsible, and in the end sails for Naath with the Unsullied who are done fighting other people's wars — Missandei's home standing in, at least, for his own.
How it ends for them
The chronicle records no death for this soul — they are living when the tale leaves them, or their ending is a page the maesters have yet to turn.
Their chapters, book by book
A Game of Thrones 1 chapter that name them
A Storm of Swords 1 chapter that name them
Where the page and the screen part
Book Grey Worm is a far smaller figure: the elected commander of the Unsullied, present and trusted — he serves Meereen’s watch and its politics in Daenerys’s absence — but without a point of view, without the romance, and without the final-act prominence. The love story with Missandei is pure show invention (she is a child in the novels), and so is his entire ending: the massacre at King’s Landing, the confrontation over Jon Snow’s fate, and the voyage to Naath have no book counterpart and cannot yet have one. The novels do sharpen one detail the show softens: the Astapori training’s full horrors, including the killing of an infant before its mother as a graduation exercise, which makes the books’ Unsullied both more pitiable and more unsettling. In both tellings he is alive — the show simply wrote him an ending, while the books have him standing post in Meereen, waiting for a queen to come back.
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.