To start: Speak to Gelakus
Reward: Ability to make evil potions. One of each kind of evil potion.
Summary: A chaos druid called Gelakus thinks he has found two herbs that can be used to make evil potions, but his farming skills aren't very good, so he needs the help of an avid adventurer to create the potions.
1. To start go to the top floor of the Chaos Druid Tower (requires 46 Thieving to enter). Talk to Gelakus, and he will tell you about these two herbs called hell nettle and sting weed that he found on a journey to the Wilderness. After some talking, he will give you one seed of each herb.
2. Now gather your farming equipment and some armour. Go to the Wilderness herb patch (south of Bounty Hunter) and plant one seed at a time. Sting weed requires 85 Farming and hell nettle requires 80. Both take 1 hour to grow. If you lose your seeds or they die, you will have to get new ones with bird nests. Remember that there is no gardener or tool leprechaun on the wilderness herb patch.
3. After you have two of each herb go back to Gelakus. He will tell you that he calculated that the potions will only have effect if you use human blood instead of water in the vial. Now get four empty vials and a syrinx (bought from the Canifis general store for 1,000 gold coins). To fill the vials with blood, you need to hit a 5 on more on another player while wielding a syrinx. It is recommended that you do it at duel arena with a friend.
4. After you have four blood-filled vials, go back to Gelakus and give them to him. He will say he calculated that the secondary ingredients he will need are: Ray sting, uncut dragonstone, ground blood rune and magic dust. For the ray sting, use a knife on a raw manta ray. For the ground blood rune use a pestle and mortar on a blood rune. For the uncut dragonstone, open the crystal chest in Taverley with the crystal key. And for the magic dust, use a saw on a magic log.
5. After you give these to Gelakus you will have completed the miniquest. The rewards are: ability to make evil potions, a life steal potion, a prayer steal potion, a life leech potion, and a prayer leech potion.