If you check the zombie corpses, you find nothing.

There are two passageways leading forwards—one more to the right, and one more to the left.

I still would consider you in combat until Aria is stable.  Therefor, if Dorno and Alexana cannot stable Aria, she would have to make a death saving throw.

Dorno watches Aria fall and calls out "purple lady, no!"  He runs over and kicks the fallen zombie in the head in defiance to keep it away from her.  He then turns and mutters a word in Sylvan as a green glow emanates from his palm and extends to Aria's body, healing her.  Dorno kneels over her and says "you are ok now, purple lady."

Healing Word 5

(You’re out of combat now.  The reason I do that is to allow for any time that might elapse before they’re stable, which can make a huge difference.  A character actually died once because of that, as the cleric couldn’t make it to them in time.)

"You alright Aria?" Thresher asks, joining Dorno in hovering over the fallen human.

"Need a rest?"

Aria groaned and stood up, "Well, that was embarrassing," she muttered. Collecting herself she gave Dorno a bright smile and said "Thank you, friend. Much appreciated." and to Thresher "I'm fine, but if the rest of the party thinks it's wise to rest and regain certain spells and abilities then I certainly won't say no."

(I assume you’re taking a short rest?)

(I would like to yes. Getting low on health.)

(Alright.  Consider it done.)

Rolling for health recovery. 10

Dorno has his default smile, or stupid grin if one prefers, already as he looks at Aria as she gets to her feet, but when she calls him her friend he suddenly grins widely and his ears twitch a little.  He says nothing however.

(Everyone roll hit dice if you want to recover.)

Rolling: 5

There are two passageways you could go in.  One that's toward the back of the room, and another in the middle of the top (if that makes sense).

A slight, shadowy figure quietly approaches the group as they rest. It's a wood elf with dark features: dark eyes, dark hair, and it looks like his face has never been washed before. He carries a bow, and initially had it drawn, but lowers it when he sees that the party does not consist of zombies. 
"I assume you folks are responsible for slaying those zombies?" He motions towards the zombie bear and other slain zombies. "My name is Miradithas," says the elf, "mind if I join you for the hunt? The world could stand to have fewer of these undead roaming about."

Thresher eyes the elf suspiciously.

"Depends; other then killing the undead what are you here for?"

The large firbolg sees Miradithas and replies with his usual low tone and slow speech.  "Hello, are you the sick rock Lord we came to help?  You look a little sick, but maybe not as sick as them."  He gestures towards the slain zombies.  "Oh, and you can call me Dorno.  Want an acorn?"   The odd natured druid hold up a thick hand full on whatever foraged bits he is snacking on.

Miradithas takes the acorn and starts to nibble at it. His social cues aren't great, so he forgets to acknowledge the gift. He looks to Thresher, "Well, I've been serving Mielikki in various ways for the past couple of centuries. I guess you could say I'm here to protect the wildlands, though some might say I'm just out to see the world."

He turns to Dorno, "I am no lord," as he finishes his acorn, "I'm just an elf with a bow." Noticing the slow speech from the firbolg, he says "You can just call me Mir. That'll probably be easier for everybody."

Dorno looks perplexed by Miradithis for a moment.  "I am like you.  I protect the forests and the fields and the hills, oh, and the harvest.  For now, at least, but I hope to see many places.  I am just a firbolg with a stick, but it is a good stick.  Ok, Mir.  You'll help us find the Lord?"

"Works for me." Aria said, simply. "City girl here, but I like the fields and the forests just fine."

“Sure, I’ll help you find this Lord. What kind of sick are we talking about here?”