Qiran realizes there is a difference between thinking he's at a safe distance and actually being at a safe distance.  He turns and sprints.

(Athletics: 20 )

The group safely makes it to the maintenance exit before the water crashes on through with time to spare. The blockage that was there further down the tunnel is utterly obliterated by the waves. Gurgling shrieks come from the tunnels as the infected creatures are washed away. The torrent is comparatively short lived, however, and soon the water level evens out; the channel that runs along the middle of the tunnel is now full, but not overflowing, where before it was just a meager trickle. The stench of rotting meat too, rapidly disappears. While it's still not entirely clear what the tunnels are for; they might be sewers, drainage for rainwater, or something else entirely. Whatever the purpose, it must have been important to undertake such a challenge of engineering.

The group has restored light to the city, and cleared out a significant infestation beneath it. While the true purpose of the tunnels has yet to be revealed, the actual taint of Tyranthraxus' forces has now truly been removed from Phlan. Faerieth can feel that the surrounding trees were able to detect the sudden change, and as the water that flows through the channels of the tunnels continues to flow, it looks progressively cleaner.

By now, however, the day is almost finished. The city council will no doubt be pleased to hear about this.

XP gains for the party: 300 each.

((Whoo! Level up!))

"Perhaps we should... return to the surface," Faerieth suggests. "Prepare to camp for the night, or... if you insist... return to town."

Qiran coughs, clearing his throat of the flehm he had built up from the run.

"I'd agree.  We've done much today, and I am feeling quite taxed."

Chroma snarls and coughs up a wad of blood. "I could do with some rest. Should we risk traveling at dusk, or is it preferred that we camp here for the night?"

"I would... prefer to stay here. In case the trees need more help."

((Do the trees that felt isolated seem to be feeling better now?))

The trees that have been 'disconnected' are calming down, the madness is leaving them. Faerieth can feel that the 'burning' is starting to leave them. It will take some time for them to fully recover, but it's like a splinter has been removed from their spirits.

Jarvo did say that the forest is safe enough if they keep to the traveled paths and don't stray too far in, and the treeline isn't far from the ancient amphitheater that the 'Luminous Chamber' was located beneath. It's still displaying a brilliant light show, which at least makes for a clearly visible beacon if they get lost.
Beyond the amphitheater are a few more ruined walls with tall, wild grasses growing between until the grip of the wild slowly overtakes the standing stone. The forest isn't too thick to camp in this close to the town proper, but any more than an hour's walk and they would be faced with the unwelcoming dense forest wall of the guardian Sanharen's domain.

Faerieth has seemed to calm down a lot, and starts looking around to see if she can find a good place to camp for the night.

There's plenty of room and resources to build a lean-to shelter and campfire, that's no problem. The only question is time, whether the group can build it before they lose all the light or not.
(Roll survival skill, passing a DC 15 means there's still daylight left by the time they're finished.)

Survival: 18

"Nicely done," Chroma rumbles to Faerieth once the camp was suitably prepared. She had been instructed in the arts of survival, but Chroma's own knowledge on building fires was lacking. She preferred the cold, being more naturally resistant to it than most. The dragonborn's ever-present frown deepens as she recalls something Harken said quite some time ago. She leans against a tree, keeping an eye out on the woods. "Something is rubbing me the wrong way about this entire situation. These were minions of Tyranthraxus, no? Alternatively, they could have been controlled bodies by whatever grubs infested the place. Either way - wouldn't the guardian of the forest, Sanharan, be interested in stopping something so detrimental to the forest? I also remember that Sanharan was harboring former minions of Tyranthraxus in her forest." She shakes her head, rolling her shoulder where the infested orc struck her. "The council will be happy to hear about this, but still."

Krinix:

"What do we know about Sanharan? Her goals and desires may diverge greatly from our own. Or else she, too, could be infected. Or distracted. One thing's for sure, though, I'm not eager to go through that process of approaching her, not any time soon."

It's been a long day and Krinix at this point would like nothing more than to withdraw a bit and work in his spellbook.

It's around this time that Jules rejoins the group and gets briefed on what the party managed to do in his absence while he was busy reporting on the achievement of solving the Luminous Chamber. It would have been nice to have the hardware store he's carrying on his back around BEFORE camp was set up, but better late than never. He sets about cooking the party a good meal for the night with the array of camping gear he's brought. It turns out the awkward human is surprisingly competent at campfire cuisine.

He merely listens to the party, and also distributes writs to them entitling each of them to 200GP worth of new supplies next time they're in town, not wanting to interrupt their conversation unless they have questions for him.

Qiran listens intently to the conversation.  He didn't trust Sanharen, but he had the impression Faerieth would give the wild entity the benefit of the doubt.  He accepts the food greedily and the writ in like fashion.

"I'm in need of steel and armor, Jules.  But inexpensive, yes.  Suggestion?"

Jules thinks for a moment.
"There's an armourer in town, a half-dwarf named Anya. She has very reasonable prices, though for 200 gold... hmmm... how heavy were you thinking?" he asks. "You could probably get a good cuiass with gambesson or scale mail, something that could be fitted and adjusted without losing too much time. Anya's fast, but not a miracle worker." he states.

(Speaking of armour, I had some thoughts about how to adjust the rules a bit to be a little more... sensible. You folks open to some more homebrew?)

(Bring it!)

Proposal for new armour/damage homebrew rules for this game:

Armour:
Because the way D&D handles armour is kind of based on old assumptions ABOUT armour and frankly doesn't do a good job of representing the protection it gives, here are the changes I'm making.
Armour, in addition to adding to your AC, also absorbs damage upon being hit UNLESS it is by an attacker who has advantage on you or your opponent lands a crit. The amount of damage it absorbs is dependent on the kind of armour you're wearing. Light armours absorb 2 damage, medium armour absorbs 3, heavy armour (Besides hide, hide absorbs 3) absorbs 4.
Armour can even absorb magic damage, so long as the damage can be described as 'force', like magic missile. Armour can also absorb damage from fire, acid, or cold damage, but only ONCE. Armour that's been damaged by acid, burning, or frost, can no longer absorb damage and must be repaired, though unless the armour is completely destroyed, it still offers the AC bonus.
ANY class can wear light armour without restrictions of any kind, so that means monks can wear studded leather armour and benefit from the damage absorption without losing their unarmoured movement/defense perk. The idea that wearing 13 pounds of protection would slow a martial artist--or anyone, for that matter--down at all is ridiculous.
Monsters who are described as wearing 'scraps' of armour or incomplete armour sets get no damage reduction. They must be in full, well-maintained armour to get damage absorption benefits from their armour.
The tradeoff, however, is that if you're traveling while carrying more than 3/4 your total carrying ability in weight, after 8 hours, you will need to make a constitution saving throw against exhaustion, and exhaustion can only be removed after a long rest, so constantly wearing heavy armour will probably drain all but the strongest adventurers.

Yes, this is mostly stuff I need to take into consideration, but I feel like keeping track of this sort of thing helps with the immersion. Rest is important, and starvation should be a real threat. I don't think of D&D as a video game where your character never gets tired or hungry.

Taking damage(revised--AKA, the Boromir rule):
Your HP basically represents damage your character can shrug off or 'imperfect hits'. Upon being reduced to 0 HP or less, your character does NOT fall unconscious. Instead, they are put into a 'desperation' state because now, they have taken a major wound and need to get help. Their will to live has kicked in, resulting in all further attacks upon them receiving automatic disadvantage as the character is more naturally defensive, though any offensive actions the character takes will not have any bonuses as they will no longer be able to muster their full strength, though if they roll a nat 20, instead of doing an extra damage die, they do x2 total damage instead. They can also still use any special abilities they have, but they no longer get proficiency or ability score bonuses in their wounded state until they raise their HP to over 0. Any spells cast require passing an INT or WIS check (your choice) against their current HP negative to maintain their concentration (so --8 HP requires a DC check of 8 to cast a spell) or be cast at half strength.
Until they are reduced to negative HP equal to their max, they are still standing. Every additional wound they take after being reduced to negative HP will require a CON saving throw equal to their current HP negative. Failing the save or being reduced to over their max HP negative will cause the character to finally collapse from shock and require death saving throws.

Players CANNOT BE KILLED OUTRIGHT by damage alone. If a level 1 thief is unlucky and gets critted by an orc to over their max HP in negatives, they go down but can still make death saving throws. A player taken down by damage will always have a chance to survive. Players can only be instantly killed by being finished off with a coup de grace while they're helpless or by failing a save to an instant kill spell or ability.

Healing damage:
Players always have a chance to be saved from death but players who go beyond their HP max in negative damage and make their saving throws cannot regain consciousness again until they reach 0 HP; so while they may no longer need to make death saving throws, they will still be down. If a player is healed while they're making death saving throws, they automatically succeed and will be unconscious but stable, but they will need more healing to fully revive. A character with a medicine proficiency can fully stabilize an unconscious victim using a healer's kit if they manage to make a medicine skill check greater than the current negative HP of the victim, so a healer with a +7 proficiency in medicine has a fair chance of eliminating all negative damage of a victim who made their death saving throws even at -18 HP. If the victim is healed for any MORE damage afterwards, they will be conscious again and able to fight.
Non-magical healing CAN be done in combat, but the healer will need to be covered for 1D4 turns to treat the wounds of a victim either conscious or unconscious. If a healer is able to apply treatment successfully, all negative damage will be relieved and the patient will be brought to 0 HP. While being treated, a negative-HP character who is still standing doesn't need to make any more saving throws.

Monster ability scores and swarm combat:
Monsters will no longer get inexplicable bonuses to attack and damage despite having abysmal ability scores. Goblins and kobolds, for instance, will no longer get +5 to hit and +2 to damage despite having 8 STR. They will have to play by the same rules as PC's.
To offset this, however, players may encounter enemies in greater numbers... but to prevent 2ed and 3.5ed dice-roll slogfests, 'weak' enemies or enemies 1 size level smaller than PC's that rely on numbers to bring down opponents will group up in pairs or up to 4 to attack, but their combined efforts count as their turn. Each additional partner grants +2 to hit and damage, and a fourth attacker adds advantage.
For instance, if 2 kobolds were to attack the same PC, they would THEN get +2 to hit and +2 to damage but will only roll ONCE. 3 get +4 to hit and damage, and 4 still get +4 to hit and damage but ALSO gives the group advantage to hit, which they would likely need in order to do any significant damage to a heavily armoured PC.
The downside to swarming for the monsters is that when it's the player's turn to attack, any attacks they make on 'swarming' enemies may damage 1D4 of them simultaneously due to their close proximity to each other.

(I have no qualms with the modifications, but how would AC be calculated with Monk's Unarmored Defense? Would the AC bonus from armor simply be added to the Unarmored Defense total?)

((It does indeed, so Chroma, wearing studded leather armour, would be standing at a very respectable AC of 21 AND benefit from 2 damage reduction as long as an enemy doesn't have advantage on her or crit. The idea that warrior monks didn't wear any armour is absurd; of course they did, and especially leather armour would still grant full freedom of movement and speed.))