In Veyr Hollow, a vast hollow sealed beneath an artificial dome called The Vault, society is divided by a single mark on the skin. Those born with a Vaultmark are recognized, named, and given rights. Those born Unmarked serve, are stripped of their full names, and die easily forgotten. All factions with power belong to the Marked — leaving the Unmarked with no one truly fighting for them. Seren Vale is an Unmarked records clerk working in The Ash Annex, the lowest level of The Last Records, where the city's death records are processed and the names of the poor are quietly erased. When an unusual body arrives with its Vaultmark cut away and three words carved beneath — THE SKY LIES — Seren is pulled back into the orbit of Alden Wren, her estranged childhood friend who carries a mark unlike any on record beneath an old burn scar on his left shoulder. A mark that doesn’t close. A mark three powerful factions will kill or capture him to control. As the investigation unravels the lies sustaining The Vault, Seren must navigate the competing agendas of the Vaultbinders, the Ossuary Conclave, and House Vaelor — none of whom are fighting for the Unmarked — while the childhood bond between her and Alden becomes something neither of them can name until it is almost too late. At the Skyline Gate, the truth costs everything. The Vault shatters. Real sunlight falls into Veyr Hollow for the first time. But memory is woven from the same lies the Vault was built on — and when the lies dissolve, not everything survives the light.