Ebon Reliquary of the Undying Mages

Deep beneath a ruined arcane archive, the party pried open a sealed alcove where four undead mages had made their vigil. Their skeletal fingers still curled around staves and grimoires; robes, hung with frost-muted runes, clung to ossified shoulders. The chamber was a small "magical treasury"—a curated hoard of ritual components, specialized inks, a few preserved spell scrolls, and objects used to bind and siphon souls for long-lingering undeath. The mages themselves were guardians and wards, not coin-haulers, so what you find is rich in arcane and necromantic utility rather than mundane plate or bulked coin. Some items are likely useful as crafting materials or ritual foci; one wand of offensive magic and a couple of usable soul-vials offer immediate power a 4th-level party can exploit cautiously.