1. Stonegarden - Ryker
2. Blackpit - entrance to the cave
In Stonegarden, you can find a mansion that belongs to Ryker. He can tell you location of a cave in Blackpit.
If you visited Blackpit before then the gate should be already opened. If not, you must open it. There are two choices. The first option is to get the key by force. If you decide to do that then you must fight with the magisters that guard the gate. When you loot one of the corpses, you can find the key to the gate. The second option is only available if you talked with magister Reimond in Driftwood and you got his written authorization. If you have it, you can show it to the magisters.
The first room contains traps that were left by magisters. There are a few ways that allow you to avoid them. You can disarm them, use Teleportation skill or use Teleporter Pyramid. In the next room you must face a Voidwoken that guards the passage to the lower level.
When you get lower, you can take a letter from a shelve. It contains orders for magisters. You can get the letter by teleporting it near your team. Move forward and watch out for a Shrieker. You can destroy him by using Source Vampirism skill. If you don't have that ability, but you still have Purging Wand that you found in Fort Joy, then you can use this item instead.
You come across a fork. In one of the chambers you can come across magisters that fight with Voidwoken. You can join the fight. However, if you manage to defeat the Voidwoken but your Persuasion isn't that high then you may have to face the magisters too. If you want to know what the magisters were doing in the cave then you can speak with a magister or with his ghost.
In the second chamber, located in front of you, you can find another group of magisters. This time, you have to fight. Here, you can also find a passage that leads to Ancient Temple. In order to open it you must set the barrels with oil on fire, the ones that are next to it.
Upon entering Ancient Temple, you discover that the entire lower level is protected by force field. The only way to remove it is to activate the statues of Gods in the right order. The solution can be found in the rhyme that is told by the object located in the middle. However, you can't solve this puzzle unless you know which God represents which element. The answer can be found in the skeleton that lying next to the object. The journal, found inside of the skeleton, contains the right match. By having both texts you can now solve the puzzle. The right order is: Amadia, Tir-Cendelius, Duna, Zorl Stissa, Xantessa, Vrogir, Rhalic.
In order to complete this quest, you must interact with the sarcophagus. This causes Eternal Aetera to appear. She tells you a bit about the Gods. After that, you must fight with her.
Reward: 31150 experience points