Deep in the underbelly of Soviet-era Moscow, a dungeon is unearthed amidst the construction of a new metro tunnel. Unknown to all but a pair of tunnel workers, the dungeon houses a cryptic artifact that could guide savvy treasure hunters to the long-lost library of Ivan the Terrible, said to contain riches and secrets beyond imagining. Fast forward to the present, where the workers' grandson, Ilya, uncovers this artifact and suddenly finds himself targeted by powerful elites who will stop at nothing to get their hands on the ancient library's mysteries. With the help of a mysterious stranger, Ilya must thread the treacherous corridors of Moscow, decipher the meanings behind the artifact's inscriptions, and contend with powerful foes who threaten to wipe him and his mission off the map. Will he survive the chase and unlock the secrets of the historic library?