When sentient, mortal beings die on Theros, they pass into its Underworld. They dwell in this eternally gray realm without sun or night under the watch of Erebos, god of the Underworld. But over the centuries, many denizens of the Underworld have escaped and returned to the sunlit realm of the living. They are called the Noston (from nostos, "to return home"), or the Returned.
To leave the Underworld, beings must give up their identity and their very faces, each of which becomes an unsettling surface with eyeholes and a mouth. This doesn't mean that the Returned have no personality and no memory of anything, however. One's name and past are forgotten, but skills and personality are retained. That is, the events and relationships of the mortal's life are lost, but the results of those events are intact (such as speech or the ability to play music). In addition, the Returned lose the ability to form the long-term memories on which relationships are based—they are unable to "build a new life," as it were.
The Returned are undead in the most actual sense. When they return to the living realm, they don't return to life. They need water and air but not food. The Returned form communities, experience fleeting emotions, and follow daily routines, but their existence is a shadow play, because without an identity or an ability to nurture long-term relationships, the elements of their "lives" have no weight or substance.
They aren't just thinking, speaking undead but also feeling ones. Although their lack of identity prevents long-term memory formation, they do feel emotions based on their experiences. That in turn means that their emotions tend toward darkness: frustration, bitterness, loneliness, resentment, anger, and melancholy.
When a human dies on Theros, a funerary mask of dark clay is customary, used to "frame" the identity of the deceased for Athreos. So when a mortal destroys his or her identity to leave the Underworld, that mortal must fashion a mask to stand in for it. Gold is the most common material in Erebos's realm, so it has become customary for the Returned to symbolically replace their funerary masks (and by proxy their identities) with beautifully crafted gold masks that cover their changed faces and function as surrogate, albeit flimsy, identities. These masks cover void faces.
The Returned have no memory of the Underworld or of their former lives. The golden masks they wear are the last gifts of the selves they left behind.
Because gold is commonplace in the Underworld, the Returned don't value it (except their own masks) and instead use special clay pieces called ostraka as a kind of currency or barter tool. Each ostrakon is a shard from a dark clay funerary mask. These pieces of clay have great significance to the Returned for obvious reasons, and they are used as mementos by inhabitants of the necropolis of Asphodel, as trophies by those of Odunos, and as ornamentation and currency by all of their kind.
The Returned refer to their two small city-states as necropolises mostly without irony - they are occupied by the dead, after all. Smaller, more isolated settlements exist, and some of the Returned eschew civilization altogether, occupying caves or simply wandering. The two necropolises, roughly equal in size, are called Asphodel and Odunos. Each has a kind of overarching characteristic: Asphodel's is despondence; Odunos's is anger.
Subraces and Variants