Capture the Castle is a main storyline quest in The Witcher 3. This quest is the final episode of the Witcher 3: Blood and Wine expansion pack. It is available right after you have completed “The Man from Cintra” quest and requires you to reach level 47 to start it.
Once you have started this quest, you also won’t be able to save manually until you have completed this entire quest. Hence, make a save file before starting this quest in TW3 Wild Hunt.
Make sure you have completed Amidst the Mill’s Grist and Warble of a Smitten Knight quests before starting the Capture the Castle quest; otherwise, you will fail both quests.
Get to Count de la Croix’s Mill
Reach the Count de la Croix’s Mill and talk to Damien at midnight to start the Capture The Castle quest. Count de la Croix’s Mill is located a few clicks directly to the east of Tourney Grounds.
Geralt will discuss the plan to siege the Dun Tynne Castle. He will elaborate on the plan in detail and show you a map of Dun Tynne.
One key thing is that this quest can only be initialed at midnight. Hence, if you reach Count de la Croix’s Mill in the daytime, you must wait it out. Once this quest is initialed, there will be some irreversible events, such as the battles of Beauclair. Hence, all the side quests will be unavailable for a while in The Witcher 3 as you progress through Capture the Castle.
You will be cut off from using the blacksmith, so stack up on any supplies you might need. Also, make sure to equip all of your preferred combat skills because you are immediately dropped into a fight once you start the Capture the Castle quest in TW3.
The first objective of this quest will require infiltrating the Dun Tynne Castle. A few guards and an archer at the gate will greet you. Taking out the archer first and then focusing on the guards with melee weapons is recommended.
After entering the gate, you need to defeat two more guards. After that, the next phase of the quest will begin.
You will encounter a lot of human enemies in this mission. It is ideal, especially if you are on Death March, to carry Hanged Man’s Venom with you to coat your steel sword and quickly kill your enemies. Grave Hag decoction is also useful.
Defeat Roderick and his men
As you make your way through the castle’s outer boundary, you will encounter a ground of guard surrounding a man known as Roderick. If you rush and attack them, you will be swarmed by all the guards.
The better strategy is to let the guards approach Geralt first. In this way, you can easily eliminate all the weaker guards before taking on Roderick.
As always, focus on the archers first, as they can be quite a nuisance while dealing with enemies with melee weapons. After you take care of all the minions, you will have a proper duel with Roderick.
Defeating him is very straightforward as he only uses basic attacks and has a little more health than a guard.
After defeating Roderick, Geralt interrogates him to inquire about the hostage women (Rhena). Roderick will tell you that there are no hostages and the woman you are searching for is in the tower. After the conclusion of the dialogue, you are given the choice to either help Roderick or let him bleed to death.
If you help Roderick here, it will be added to the list of Proof of Compassion for There Can Be Only One, which is a quest needed to complete if you wish to get Aerondight. So, I would say that helping Roderick is the best choice to make at this point in Capture the Castle.
Defeat the guards and reach Dun Tynne Castle
Move on to the next area, where you will encounter a group of guards with dogs. These enemies are slightly stronger than the guards in the previous area.
There is an enemy known as “Iron Borg” among these guards. He can hit you especially hard and has considerably more health. He is armed with a giant, two-handed, long sword.
Kill all the other enemies and leave him for the last. Iron Borg attacks hit hard but are clumsy. Therefore, you can easily find an opening just by dodging his attacks.
After taking care of all the hostiles, march to Dun Tynne Castle. There, you will encounter some weak guards that can be easily taken care of. After which, you will find Regis and Dettlaff in the castle.
Capturing the Castle can bug out here sometimes, and the cutscene when you reach the tower doesn’t trigger. Just wait a bit, and the quest step will automatically progress.
Now you need to only walk with them to the perch as your vampire allies will take out any enemy you encounter promptly. However, if you want to get your hands dirty, nothing is stopping you.
Make sure you aren’t using any mods or have a save slot prior to this quest. The upcoming cutscene that comes at the end of Capture the Castle can be quite buggy and cause the game to crash if you have mods installed.
Once you reach the top of the tower, the final cutscene of the quest will be triggered. It is a meeting between Syanne and Anna Henrietta. You will make a few choices in this cutscene that do not really impact the ending. They are more for your benefit as you will get a better insight into the matters.