The Old Watcher

 is a main quest in.

Synopsis
The spirit of Caldara de Berranzi, one of Lord Raedric's unfortunate victims, has directed the Watcher towards Caed Nua, where I will find a man named Maerwald. Caldara has informed them of their newly found status, and that this Maerwald is a Watcher as well.

Walkthrough
From Gilded Vale, travel east across the Black Meadow to Caed Nua. Talk to Kana Rua, who is standing by the gate, and recruit him to your party. Make sure you understand how to play chanters so you can make good use of him. Consider positioning him at the back of the party where he can pick off enemies with his slow but very powerful arquebus—especially useful against the monsters infesting the above-ground area of Caed Nua, who are mostly resistant to normal weapons. For a lower-level party, these enemies are relatively difficult, including shadows, phantoms, will-o'-wisps, and blights; they can be particularly dangerous for Aloth or any ranged party member with low damage resistance due to their tendency to circumvent the frontline of the party, and it may be worth equipping these characters in heavy armour and sacrificing attack speed for protection. It is possible, however, to avoid most of these encounters by careful scouting: generally, you will only need to fight one time outside if you proceed directly to the keep in the northeast.

Once inside, you will quickly be engaged by a group of spirit enemies just to the northeast. After dispatching these, speak to the steward who inhabits the throne at the front of the hall and then proceed to the dungeons through the door that has just opened to the northwest. The dungeons are quite a small map, but tred carefully nonetheless if you're on a higher difficulty level—there will be a large number of spiders here and it's wise not to engage too many of them at once. Exit southwest and you will enter level 1 of the Endless Paths of Od Nua.

Most of this map is irrelevant for the purposes of the quest. Maerwald is located in a locked room immediately to the northwest, next to the raider ghost—hold tab to highlight the door if you have trouble seeing it. If you or a companion has at least 3 mechanics, you can pick the lock on this door and ignore the rest of the map entirely. Otherwise, go a little to the southeast until you encounter a group of xaurips. These should fall easily, and the key will be among their bodies.

Make sure to save the game before talking to Maerwald, since he will start fighting you as soon as the dialogue with him ends. There is no way to avoid this battle: Maerwald must die. He will summon blights and cast powerful spells. Try to keep the blights occupied with Edér or another high-endurance character. He should be defeated relatively quickly if you focus firepower on Maerwald himself rather than his summons, but he is a strong opponent compared to what you will have likely encountered up to this point, and fighting him may require careful tactical management of your party. Heal generously and cast whatever debuffs you have available. You may also distract him by having Kana summon skeletons.

Once Maerwald is defeated, you will be given three choices for what to do with his soul.
 * You may release his soul, which provides a permanent bonus of +2 prestige for your newly acquired stronghold.
 * You may bind him to the keep as a warden, which provides +2 security;.
 * Or you may absorb his knowledge, which grants access to a secret room by the round table on level 13 of the Endless Paths.

Bear in mind that unless you are extremely overleveled you will not be able to make your way to this room for a long time ahead. Make sure to pick up the grimoire from his body, which may come in use for you or your wizard companions. Also note that in, the choice as to what to do with Maerwald determines the difficulty of the Rite of Passage, as the third battle is against a memory of Maerwald conjured from the Watcher's soul by the Faces. Releasing him makes the combat easier, while eating his soul for the knowledge will make the combat severely more difficult.

The quest will complete once Maerwald is dead. To claim your prize, however, and get started on Never Far from the Queen, return to the steward on the ground floor of the keep and speak to her again. You will be given control of the stronghold as well as access to the lower levels of the Endless Paths. Do as she tells you and upgrade the Eastern Barbican. This will let you proceed southeast towards Defiance Bay.