The party makes their way towards the tower, their steps virtually silent on the water due to Brother Siegfried's spell. Vitha, when it's explained to her, declines the spell, preferring to swim silently, when she's not guiding the party. Now that you're out among them, the tufts of grass are actually over 5 feet tall in most places, so your approach to the tower has been mostly behind cover.

The swamp spreads out further to the west, but near the tower you are able to find more rocky, dry (or at least unsubmerged) ground. As you get within earshot of the base of the tower, Vitha hisses a warning and you drop behind a large tuft of grass. 

You can hear a growling, snuffling noise as a massive rot troll, larger than the two you had previously defeated, emerges from the base of the tower. It looks around and seems to catch a scent before looking to the north and starting to walk. Its trudging path, straight through the water and grass will take it directly through your hiding spot, though it doesn't appear to have sensed your presence.

Vandeyr hands the potion of resilience (+1 ac for ten minutes) to Tor. 

He then prepares to cast Faerie Fire as soon as this troll is in range.

DC 16 dex save

Tor gestures for the others attention, pats a hand calmly, then points to the troll, to the area they stand in which the troll will soon pass, then brings a hand down in a chopping motion. 

Wait until it is right here, is the message.

He then gestures for Rawlings and Vandeyr to take position a little further back down the 'path' they have just taken, and for Siegfried to take position off the path here. He will position himself as close to where the troll will pass as possible while still being hidden.

If we're rolling for stealth he will activate Merge With Stone, as they become just another part of the swamp.

Stealth: 32

He will also drink the potion of resilience.

Vandeyr is on board with this plan. Fast and well done! 

Stealth 10 +10 for Tor's pass without trace 

(You'll definitely take it by surprise, so if you haven't already, go ahead and post what you want to do in the surprise round)

Tor will hold his turn until last, waiting until all ranged attacks have taken place, at which point he will emerge from his hiding place, maul in hand. Given the size of the thing, he'll focus his attacks on its legs and lower torso.

I'll do two rolls for each attack, to preempt Faerie Fire, but if that doesn't happen just take Roll 1 for each.

Attack 1 Roll 1: 8 Damage: 16

Attack 1 Roll 2: 19 Damage: 8

Attack 2 Roll 1: 21 Damage: 11

Attack 2 Roll 2: 25 Damage: 8

If Faerie Fire does happen and they're STILL terrible rolls, I'll add in a Precision Attack, but I'll wait to see what happens first.

Brother Siegfried sees Tor signal the plan.  He looks back toward the water helplessly, afraid to vocalize his own idea for fear of alerting the troll.  The surprise attack unfolding, he joins his allies.

He rises and casts guiding bolt (upcast at level 2) Attack: 12 Damage: 17  If Fairie Fire grants advantage, here is another roll: 22

Should Fairie Fire fail but the Guiding Bolt succeed, the next attack on the troll has advantage.

Rawlings sees Tor's signals, moves to where he wanted the ranged attackers placed and as soon as the troll is 'here', Rawlings sets off her eldritch blasts.

Attack: 17 Damage: 6

Attack 2 if applicable: 19

Attack: 11 Damage: 14

and again: 27

(Sorry, it's been pretty busy at work recently)

Dex save: 16 vs. Faerie Fire

The troll is suddenly limned in glowing light, making it's every feature standout sharply. Every attack against it seems easier.

Within a second, Brother Siegfried's bolt crashes into the monster further glowing in its side like a bullseye.

Rawlings' Eldritch Blasts drive home in the center of that bullseye, tearing flesh from the monster's chest.

Vitha stands and looses an arrow, her expertise at hunting these particular foes guiding her to hit it where it most hurts:

Attack: 21 Damage: 13

Finally, Tor wades out into the battle, his maul crashing into the troll's hip and his back swing buckling its knee.

Vandeyr initiative 15 

When his turn comes up, he's just going to blast away with a fire bolt (at advantage! Yay faire fire)

Attack: 27 Damage: 5 

Tor initiative: 18

He continues his assault on the troll, swing after swing. The flickering fire effect which outlines it is a huge boon in this dank swamp, glowing even through the choking haze of stench coming from the troll.

Attack: 13 Damage: 8

Attack: 26 Damage: 10

Quote from EMIW >>

Tor initiative: Dice rolls not yet available for this section.

He continues his assault on the troll, swing after swing. The flickering fire effect which outlines it is a huge boon in this dank swamp, glowing even through the choking haze of stench coming from the troll.

Attack: Dice rolls not yet available for this section. Damage: Dice rolls not yet available for this section.

Attack: Dice rolls not yet available for this section. Damage: Dice rolls not yet available for this section.

 It didn't read your rolls, or there's something weird going on

Oh dear, let's try again:

Attack: 21 Damage: 11

Attack: 25 Damage: 12

Initiative: 9

Rawlings Initiative  8

And she attacks with the eldritch blast again..

Attack: 20 Damage: 14

Attack: 12 Damage: 6

Initiative: 13

If the Troll still stands, Sigi follows up with another guiding bolt (level one this time).  Attack: 28 Damage: 28 radiant.

Troll damage taken

 Vandeyr's bolt burns into the trolls chest, distracting it as Tor's maul catches it on the hip and his backswing snaps against its chest.

As it catches itself from falling and roars in pain, Rawlings' eldritch blasts burn rows along its outstretched arm.

Before it can even close its mouth, Brother Siegfried's guiding bolt catches it in the chest and blows a hole through it. The troll falls dead, it's deformed body floating in the water.

...Vitha lowers her bow and gently releases the tension and replaces her second arrow in its quiver. She tilts her head and turns it to be able to see each of you before shaking her head and muttering something under her breath, Vandeyr thinks he heard her say something like, "may yet survive this."

We are out of initiative, and there are no other threats immediately present.

"Good job everyone," Tor congratulated. "Let's hope the others go down as easily." 

He wipes the gore from his maul onto a patch of grass, before turning to the others again. 

"Anyone need any rest or prep time, or are we good to keep moving?"

Vandeyr will start walking towards the tower entrance, eager and watchful for signs of enchantment.