Sinister key

The Sinister key is used in Yanille Agility dungeon. It is dropped by Salarin the Twisted but is also a potential loot from catching a Magpie impling, as well as a possible reward from the Triskelion Treasures Distraction and Diversion. It is used to open the Sinister chest that contains 9 grimy herbs: 2 harralander, 3 ranarr, 1 irit, 1 avantoe, 1 kwuarm, and 1 torstol.

The market value of the sinister key is linked to the market value of the herbs that it unlocks.

Dropping monsters
Sinister key