Quest: A False Accusation

dead are raising in a town only an hour after theyve been killed. when the party arrives they claim that theyve already found the culprit, a shadar-kai woman, but she swears it isnt her fault. they have to help her find freedom and also find the real cause- a strange magical symbol carefully carved into the central tree of the graveyard, an odd curvint spirally shape. As they try to remove it, they're attacked by a https://forgottenrealms.fandom.com/wiki/Bodak who draws out from under the ground. It's gross!
This Bodak underwent some strange, terrible fate- it was a Shadar-kai in the shadowfell who was forced to commit evil by some whispering monstrosity. He transformed into this fuckin' thing and was then recruited by Aspen to help him with his quest. He was sent to the town to start raising an army.
https://roll20.net/compendium/dnd5e/Zombie#content

Plot points/Scenes

Intro
The party members make a perception roll, just in case. In the lounge or docks, roll a 15 or above on perception to see a little black-backed jackal with a leather collar on running it's way to the plateau. It's holding a stone that's addressed to Rane Arriene⁣⁣⁣ - if used by another person, a deepish voice comes out that says to return it to the correct owner or face consequences unimaginable.
Whenever the jackal does make it's way to Rane, they look at the stone and recieve a message from Yine⁣⁣⁣ ne. It asks Rane to send a party to investigate the town of Barrow⁣⁣⁣ because of the strange undead occurences it's been suffering from. He clarifies that anyone who dies in the town returns as a zombie within ten minutes- and since the town is relatively large, it's been kind of a fucking issue.
After recieving the message, Rane sends a hawk to retrieve the rest of the party and explains the situation. Assuming they accept, they're sent out to the town of barrow!

Travel: 
The town of barrow is south of Wes'Hn, in the southern deserts. It's described as a large town and sister city to Wes'Hn, though not nearly as large. Much more peaceful, though similar worship of Osiris and Anubis occurs there.
Traveling there, the party may run into bandits, Sol if they roll a nat 20 on perception, or even a travelling trader named Jou and his strange warforged companion from Veilan. They'll be selling all kinds of magic trinkets.
https://www.aidedd.org/dnd/monstres.php?vo=bandit-captain  https://roll20.net/compendium/dnd5e/Bandit
Jou- Half Genie man, deep brown skin and short forest green hair. Wearing a LOT of scarves and a heavy jacket. Is fucking SHREDDED under the jacket and has an insane amount of tats.  Clover- Strange robot unlike anything the parties ever seen. Clockwork, victorian fashion. Quiet. Built in Veilan, traveled here with her master, fixed up by Jou.  Bell- Cute lil strider bird thing. Likes food.
https://www.reddit.com/r/dndnext/comments/4mijqx/100_slightly_magical_trinkets/?st=k3asw9n8&sh=7810fc5e⁣ 
The Town
See Barrow 
Upon arriving, the party sees there's a huge stone wall built up around most of the city. On their arrival at the front gates, they run face to face with a zombie slamming itself against the walls. Before they can attack, an arrow sinks itself into the zombies throat. A guard calls over the gates and asks them what their business is.
If they explain they're with the Hekan Guard, they'll be allowed in.
Inside, here's the situation: Over the last three days, the dead have been coming back to life as zombies. It's been difficult, but they mostly have it under control! The captain of the guard, Grendan tells them it's been solved. They have the culprit locked up right now in the guard quarters, and they're going to be excecuting her within the next day or two. She's a shadar-kai woman who the guard insists is a necromancer.
The woman has bars in the guard station if the party isn't able to convince the captian to allow the party to speak to her. There, they meet Maurr . She's a shadar-kai with a shaved head, odd dress, and LOTS of piercings. She's wary of the party, but eventually explains that she's just a traveler from Dodeik who has nothing to do with the curse. She's a cleric of the raven queen, and hates undead with a burning passion. The party is then tasked to figure out the real cause before she's executed in two days.
Actual Shit That's Happening: In the city's graveyard, the central tree of it has a strange symbol carved into it.  a strange magical symbol carefully carved into the central tree of the graveyard, an odd curving spirally shape. It was carved there by a Bodak who snuck into the town at the dead of night, stumbling thru the town and scaring some of the townsfolk. 
This Bodak underwent some strange, terrible fate- it was a Shadar-kai in the shadowfell who was forced to commit evil by some whispering monstrosity. He transformed into this fuckin' thing and was then recruited by Gerenth Ryback to help him with his quest. He was sent to the town to start raising an army, crawled his way into town thru a passage into the underdark beneath the desert. The passage is located in a corner of the town with an old abandoned guard tower. 
Hints: Townsfolk in the inn, the gravekeeper, and some of the city guard will tell tale of strange noises and deaths in the previous weeks. There's rumors of some monster that's been wandering around in the night, but nobody has actually gotten sight of the thing except for a specific townsperson who lived near the graveyard named Orrian. He was a young human. Upon trying to find them, the crew run into their home and find their corpse- it seems like they've been killed. However, upon speaking with dead, it will say that it saw something walking out in the graveyard, this strange human with a gaping open mouth and eye sockets and horribly deformed limbs. 
In the graveyard, there's four or five zombies milling about. The graveyard has a few trees, with one big one central to it all, along with some shrines to the gods Anubis and Osiris. The shrine of Osiris seems to have been desecrated by some inhuman thing. 
Once they see the tree and try to destroy the symbol, the Bodak attacks.
8 zombies, 1 bodak, 2 girls, 1 cu-
Upon further inspection, the symbol seems to have caused the zombies to rise, but also seems like it might have some other purpose. A high roll on arcana might allow the party to tell that it's used to open some kind of portal, if used in conjunction with other symbols of the same kind.

Parent Plot

MASTER PLOT: The Rise of the Black Snake