Skeleton Key (Skyrim)

The Skeleton Key is an unbreakable Lockpick, obtained during the Thieves Guild quest, "Blindsighted", after killing Mercer Frey and looting his corpse. It must be returned to the Twilight Sepulcher (Ebonmere) to complete the remaining quests for the guild.

Tips
Keeping the Skeleton is advisable if the Dragonborn's Lockpicking skill level is below 100. While using the Skeleton Key, the Lockpicking skill still increases, opening up an easier way to maximize the skill. Additionally, Vex offers burglary quests where the Skeleton Key becomes very handy.

Quests

 * Blindsighted