And the moss is still alight, preventing the Troll's regeneration.

Erix and Mark are up.

The dire wolf attacks first trying to get it down on the floor again:

Crit(25)-> 13+7=20 dmg and DC13 str save or be prone
Boar: 19 for 6dmg (2nd roll if prone: 15)
Clumulk: nat 1, if advantage: 17 for 7 dmg (Overwhelming attack)
Land beast: (8,22)-> 22(pack tactics for adv) for 12 dmg

Erix himself than goes for another Thorn whip:
(13,13)->13 for 2dmg.

Mark with a slightly unhinged smile pulls out his crossbow and shoots at the Troll 

Attack: 17

Damage w/ sneak attack: 8 + 11 = 19 dmg

The Troll never stood a chance. From your continued assault, its ripped apart by Erix' animals, and Mark makes the killing blow with his crossbow. The giant lies dead on the floor.

What is the plan now? How does Elero and Erix act to Mark's sudden shift in behavior? 

Mark will look at the Troll and try to burn it with any fire that is left. He will do this silently.

"Wow," Elero mutters. "That went much better than I thought it would."

He'll watch Mark warily. "How do you feel now, Mark?  Is your quest over, or is there more to be done?"

Mark turns to look back Elero, fire giving him an unnatural underglow, "I am fine, friend, but the quest will not be over until there are no living beings in this sacred place." Then he begins to smile and moves forward, deeper into the unknown.

((Can we roll something to remember how we might help Mark? (besides fullfilling the quest of course)))

Erix Religion check: 16

It's hard for Erix to deduce what might be afflicting Mark at this time.

Reminder the hallway to the east has three exits to the north, south, and further east. The most used door seems to be the southernmost.

"Mark, are you willing to plan with us, or are you being called in a particular direction?" Elero asks. "Can you explain what you're feeling right now, and who's telling you to do this?"

Elero and Erix sees only for a second the discomfort and fear on Mark's face as if he is trying to fight something that is in him. But it goes as quickly as it came. He then says, "We should go to the south, believe that is where we must go."

Are Elero and Erix following Mark?

Elero can't think of a better option, so he's going to ride the whirlwind, all the time thinking to himself that one should never spill one's blood into a strange bowl.  Lesson learned.

Erix follows along aswell still wondering how they might help Mark get out of this.

Quote from bird94 >>

Elero can't think of a better option, so he's going to ride the whirlwind, all the time thinking to himself that one should never spill one's blood into a strange bowl.  Lesson learned.

 (This made me laugh) Mark will move with assurance but will whisper to himself as he walks.

You open the door and find yourself in a room full of curio. Chests and urns are arranged in clear order around the walls, and several more stand in the middle of the floor. The only exit from this room is a door to the south which has two locks on it.

Elero will look at Mark, and so will his tiny, mechanical dragon.

"What now, fearless leader?"

"Give me a moment as I wait to hear for the right move." I am waiting for DM Inspiration.