The Final Trial Witcher 3: Wild Hunt Quest
Suggested level: 19
Group: Main Quests
Location: Kaer Morhen
You'll get this quest after you speak with Vesemir when you get to Kaer Morhen in the "Ugly Baby" quest.
The task of preparing the phylactery fell to Lambert, to his great dissatisfaction. His discontent came as no surprise to me when I learned of it - Lambert was not the most obliging of fellows, and Yennefer, well, let us just say she was not his favorite individual. Nevertheless, Lambert agreed to do the job, and Geralt felt he had no choice but to accompany him.
Related points of interest
Lakeside Hut
Kaer Morhen
Cave of Trials
Kaer Morhen
Quest stages of The Final Trial
1. Find Lambert.
You will find Lambert in the main chamber of the upper part of the castle.
2. Return to Lambert when you're ready. / Follow Lambert.
When you're ready, tell Lambert about it and then follow him until you reach the Lakeside Hut pier where he says you should find his boat. On the way you will have to get rid of a few harpies (19) that will stand in your way. When you get there, you will find out that a strong wind has taken the boat and you have to look for it.
3. Find the boat. / Kill the drowners. / Kill the water hag.
Go along the lake and you'll soon find the boat. To use it you must first get rid of a few drowned dead (18) and then the a bilge hag (20).
4. Get in the boat. / Sail across the lake with Lambert.
When possible, get in the boat and sail with Lambert to the other end of the lake where the entrance to the Cave of Trials is located.
When you get ashore, you'll hear a child calling for help. Lambert will suggest it might be an illusion and you can ignore this call or decide to check it.
5. (Optional) Check where the boy's voice is coming from. / Kill the foglets.
If you go along the shore to check where the boy's voice is coming from, then you'll find a little boy who, as Lambert predicted, will turn out to be an illusion. You'll be attacked by three foglets (18) who prepared this ambush and you'll have to kill them.
6. Enter the cave. / Go through the cave. / (Optional) Kill Old Speartip.
Return to the cave entrance, enter it and move forward. While wandering around the cave you will find several walls that can be destroyed with the Aard sign. Geralt will say it's better not to do it because you can wake up Old Speartop doing that, but I don't think it's possible so you can do it if you want. But if you don't want to risk it, you can bypass the rocks by climbing the nearby ledges.
At some point you will reach the big cavern where Old Speartip should sleep. You can approach him and attack him, but you can also sneak to the nearby exit from the Cave of Trials.
If you decide to kill him, just approach him and he wakes up.
7. Get to the Circle of Elements. / Seek shelter in the tunnel. / Get past the blockage. / (Optional) Kill the trolls.
Soon after leaving the cave, you will come across the trolls that will not be willing for you to enter their territory. Even if you try to be nice while talking to them, Lambert will make the trolls angry and they will eventually start throwing rocks at you.
Quickly run to the nearby tunnel. Inside you will find a wall you can destroy with Aard sign.
Once you pass this small cave you will encounter the trolls again. If you try to resolve the situation peacefully, the trolls will agree to let you pass if you give them your weapons. You will be able to retrieve them on your way back. Of course you can also decide to fight and kill trolls (17,18,21).
8. Put the phylactery on the altar. / Light the torches around the altar.
Come up to the altar. Place the phylactery on it...
...and then light four torches arount it.
Once the phylactery is charged, you can go back to the castle together with Lambert or stay where you are. In both cases, the quest will be completed.
Geralt and Lambert braved the dangerous path to the Circle of Elements, which took them across a drowner- and foglet-infested lake, through the cave in which Old Speartip slept, and over mountain passes home to mistrustful and treacherous rock trolls. Along the way all the differences between Geralt and his younger comrade were exposed in sharp contrast. Sparks flew between them more than once, and biting commentary and barbed remarks were the order of the day. Geralt tolerated Lambert's prickliness with admirable stoicism, for he knew that the younger witcher's famous sarcasm served only to cover his many deeply-felt, never-healed wounds.