Before the Light of Tyve campaign begins, the Game Master presents Tyve as an ancient continent within Nabell that was shaped by Vorax, God of Earth, and A'feros, God of Fire. They belong to the six Dead and Buried Gods alongside Solarus, Ordos, Ea, and Umtheras, all of whom have vanished from the world while their descendants, dragon gods, and lesser divinities remain. Vorax taught mortals to forge weapons with A'feros's fire, provoking A'feros to create Kypheron and unleash him against mortal life. Solarus eventually touched Nabell within the center of Tyve, creating the Ithelion, a source of tangible divine light. The resulting fulmination sundered the land and scattered light-infused stones called glints across it. Solarus then created the Vey, a peaceful and deathless people who defeated Kypheron but spared him, persuading A'feros that mortal life was worth preserving. Thousands of years later, the Vey, A'feros, and much of this history have disappeared from common memory.

An expedition entered Tyve centuries before the campaign, returned from the sealed interior with a portion of the Ithelion, and established the societies that became the five great Houses. The light was placed within the Lighthouse of Piln, from which it illuminates much of Scarsden and helps protect the archipelago from the Plague. A supernatural storm subsequently enclosed Tyve, cutting it off from the wider world and wrecking nearly every vessel that attempts to cross it. The mainland's mountain wall and the sealed Dio Ostium prevent access to the continent's center, though a distant radiance remains visible beyond the peaks. Tyve itself is cold, overcast, volcanic, and scarred by sulfurous gases, bogs, and diseased lands, while the Vented Sea around Scarsden remains tropical and rich with fish. The five Houses are the Stewards of Gavra, Cult of the Iron Chain, Sorcerers of Keph, Plague Artists of Slyphus, and Forgotten Dead of Dragdah. Gavra, ruled by Marquis Selendra Cassiandros, maintains the strongest navy and a limited parliamentary system, but its fear of contagion has produced extreme xenophobia, hostility toward magic, and the immediate burning of anyone suspected of carrying the Plague.

The discussion introduces the travelers whose separate paths will converge in Scarsden. Whisper, a young thief raised by his imprisoned grandmother, carries a mysterious key left by his mother and believes it will someday unlock his birthright. His companion Ernan Baldomar hides chain-shaped burns beneath his sleeves, masks an unknown trauma with flirtation and fearlessness, and supports Whisper's search without explaining his own past. They hire Bjorn, the former chieftain of Norn, whose people fled the Iron Chain and founded New Norn after he left his beloved behind. Bjorn seeks money for an expedition to find a cure for his secretly infected niece and regards his own battle rage as a dangerous failing. Elsewhere, the Umtheran ethomancer Vyr and the Vanari ranger Helena have traveled together for several months after surviving a confrontation in the Undying Lands. Vyr belongs to the Blades of Nos but carries a forbidden ability to siphon life, while Helena comes from a nearly immortal civilization beyond the mists and believes Solarus's lost light may guide her home. Normandy Borthal enters the story as an elderly but inexperienced wizard, and Torrin is introduced as one of the forgotten Vey, a twilight cleric from a people erased so thoroughly that no surviving culture remembers they existed. These characters begin in a land where ordinary resurrection has failed, magic requires dangerous conduits, death carries lasting consequences, and the light that promises salvation also creates monstrous shadows.