Torstol may be obtained through the Farming skill, by planting a torstol seed in a herb patch with 85 Farming. Torstol seeds are very rare drops, but nevertheless farming is the most common source of Torstol. Torstol may also be obtained from the sinister chest in Yanille's Agility Dungeon. To unlock the chest a player needs a sinister key, which is a drop from Salarin the Twisted and a possible item of loot from magpie implings and nature implings. Before the release of the Farming skill, the sinister chest was the only way to obtain torstol.