Heavenly Secrets BureauEP 18

The son of a convicted astronomer from the Imperial Observatory follows the clues left in his father's secret notes. Teaming up with the Ninth Princess, a skilled healer, they unravel a series of bizarre cases involving witchcraft, divine lightning, and earth-shattering sorcery. But as they peel back the layers of mystery, all signs point to a prophecy in the mysterious tome —the prophecy that says, "Two Fish Doom the Nation."