In the dungeon, just after the first corner you meet few guards. If you have a distance weapon you can make few shots before they notice you.
Get into Mors' cell where your paths cross for the first time. Alester kill executioners quickly and you'll have a moment to explain everything.
But the joy won't last long Endrew sneaks into the cell and kill (this time for real) Gawen.
After that, new companions (Mors and Alester) start fighting with the spy and his people. If you listened to my advice in the previous chapter, you won't fight with your bare hands.
Alester and Mors are deathly duet, so it should be easy use their skills. Area stunning make it even easier. After battle collect loots, especially Endrew's sword.
Next step is regaining Mors' warg. He is nearby the cell in which he was initially kept. Kill the guards. From now on you have a warg mode available again you can follow Jeyna's scent to find her in the Castlewood.
Girl's scent leads to upper dungeon level.
If you finished secondary quest The Maggot in the Apple, guards here won't be a threat, and Alester kills them immediately. Otherwise, the encounter will be tough.
Stop on the landing and use R'hllor's Vision to find a secret passage. It isn't necessary but makes cleaning up this level easier. Find the single enemy on the other side of corridor and kill him before moving on.
Thanks to eliminating him, two enemies on the next landing won't be a problem.
On the ground floor another group of enemies attack you. Eliminate those on the bottom, the rest will come for you.
It will be tougher on the landing. Use area skills of both your warriors to win almost harmlessly.
First enemy on the next floor can be bit to the death by Mors' dog or just stabbed.
Next enemies are hiding in the nearby room. Fight with them isn't obligatory, but it means additional XP and loots.
Opposite to an entrance to the room on the first floor, you may find a secret passage using Alester's skills. You don't have to go this way, but it'll make the next floor easier and let you find a hidden treasure (dog will sniff it out).
If you used the secret passage, walk in the chamber on the 2nd floor as a warg and kill the enemy showing his back to the hall.
Then open secret door leading inside and eliminate rest of guards. One of them (in heavy armor) has a key to the 3rd floor. After encounter follow the scent on the next floor.
In front of the door should stay one man, who can be easily killed.
If you omit any loots on the way here, collect them now because entering the chamber begins the final of the chapter and return won't be possible without loading the game after a long cut scene.
In the chamber you meet Marianne Harlton and Jeyne. Alester will put a knife to Mariann'es throat, like his brother earlier.
When Lord Harlton rushes in the room, you have a choice:
- kill Marianne, what avenges Gawen's death (Alester choice)
- spare Marianne (Mors choice)
If you kill Marianne, Alester gets a trait Ladykiller (Critical Damage +2%). If you spare her, Mors gets trait Kindhearted (Chance of critical hit +1%). Choice is yours.
Independently of what you've done, Harlton orders to kill you. Brave Jayne protects you with her own body, knowing, that he is too precious for the lord.
Mors and Alester use the situation to jump out of window, what ends the 10th chapter.