Here are unclosed story arcs I found. There may be others.
Addendum: I have added the closing approaches that we play tested. Anecdotally, these seemed to work as the players (mostly in their 30s and 40s) cheered at the end of the adventure which, given the last minute coverage as a DM, was a relief.
OPEN ARC:
Ubtao and the Nine Gods --> As Acererak is vanquished or routed, there is little mentioned about how the Nine Gods, who have possessed various PCs, leave their hosts, what they say or how they convey the reward for those who get to keep their special weapons. What is missing is how might DMs close these arcs.
OPEN ARC:
The Airship Crash Survivors --> The PCs found a crashed airship in the jungle. The crew had failing health, no food, and a broken ship. Their story is left unclosed after being saved. DMs can answer the question how does one close this arc in a meaningful way for the players? -->
...PLAYTESTED CLOSING:
We modeled this similar to the end of Lord of the Rings. In LotR, when it was clear the ring has been destroyed, three eagles are sent to pick up any possible survivors. The eagles find two survivors. One eagle flies back without anyone. Thus, for this adventure, once the soulmonger was destroyed, we anticipated that diviners and others the world over would know resurrection works again. We placed that airship and their crew as haven taken the risk to fly to the Tomb and wait outside like the eagles to pull up the battered and bruised PCs. ”We are honored to be here and greet the heroes...” The airship returned to Port Nyanzaru. On the way back, we had the PCs see the rest of the impacts that they have had on the world with zombies walking aimlessly into the water and being torn about by dinosaurs. Villagers below were seen digging people up from graves and priests were seen resurrecting people. Giants were seen leaving on long boats with their dead.
OPEN ARC:
The Clone --> A clone of a PC is found beaten and bloodied, tortured by the witches, and deformed but with all the memories of the PC. Andrew Stanton, in "The Clues to a Great Story" says the core principle of great stories is "Make me care." DMS can answer the question, how do we finish the arc of the Clone and make it so the PCs might care? -->
...PLAYTESTED CLOSING:
The pit-fighter PC who was cloned in our party was creeped out by the Clone. Whereas the rest of the party cared about the abused Clone and actually freed it from its cage. To give the Clone an arc and a chance at gaining that last PCs empathy, we planned to have him throw himself in front of one of the Soulmonger's tentacles saving his clone "brother" from being thrown in the lava. The Clone was to take heavy damage in the lava and be additionally scarred - but the scenario never presented itself. Instead, at the end of the fight he told the party he will leave pit-fighting to his...he's unsure what to call his cloned brother...and instead "wants something a bit more peaceful. Maybe run an inn up in the mountains. If I ever get one, you can always know you are welcome and have a place to stay." The "brother" was still creeped out - but the party wished him well and said they would visit.
OPEN ARC:
Strawbundle, Clay No-Face, Joho --> The party found children with souls trapped in dolls who are slaves of the witches. The party freed them from witches. DMs can answer this open arc around how does their story end and how to convey it to the PCs?
...PLAYTESTED CLOSING:
The dolls rode back with the PCs on the airship, looking down at a world they have never seen. They tugged at the legs of the PCs pointing out sights that stunned them. We considered that the three dolls were a new odd family straight out of a Tim Burton movie that might ultimately leave for the world of Fey - but instead we had the temple priestesses in town promise to give them a home and promise they would work to restore the dolls to their childhood bodies.
OPEN ARC:
The Monodrone --> In ToA a Monodrone is released into the Prime Material Plane with no clear way to get back to Mechanus. Blinking and in fear, it clung to the edge of the bureau, clicking and whirring unsure what to do around the PCs.
...PLAYTESTED CLOSING:
--> Our party became quite attached to the Monodrone. "He's a cute little guy." He'd been following the players because he was lost. The PCs freed the Dao who before the PCs departed on the airship offered to return the Monodrone to Mechanus. They said goodbye to him: he made gear sounds.
OPEN ARC:
Artus and DragonBait --> Despite being hunted by Frost Giants for the Ring of Winter, these NPCs can ally with the PCs and help them on their quest to defeat the Soulmonger. Yet, little is mentioned how the story finishes and how they finish their alliance and story in a compelling way.
OPEN ARC:
The Frost Giants --> searching for the Ring of Winter, the PCs meet and fight some of them. This has a middle but could use a story arc for their encounter.
...PLAYTESTED CLOSING:
---> We chose to close both Artus & Dragonbait and the Frost Giants in a single scene. As the PCs traveled across the jungle in the airship, they saw the Frost Giant's longships leaving Chult for now. Artus said, "They are leaving. Maybe they too have friends or family they wonder if can be resurrected." He then looked at his ring and said, "They'll be back."
OPEN ARC:
Undead --> There were tens of thousands of undead wandering across the land, bound, potentially, by Acererak's power. DMs can answer the open story question was there any effect on the land of Chult with Acerak's setback?
...PLAYTESTED CLOSING:
--> The undead became temporarily aimless and torn apart by dinosaurs. Floods of undead were seen walking into the sea.
OPEN ARC:
Families of the Dead --> Families have been suffering across the world. People gave up hope and buried the dead. Graves are filled with the bodies of the un-resurrectable many which now become resurrectable. How best to show the impact that the PCs have had on the people's lives?
...PLAYTESTED CLOSING:
--> As the PCs entered the city by airship, they could see grave sites being dug up all over. Priests stood nearby over the exhumed bodies to cast resurrection. People were hugging lost loved ones brought back from the dead.
OPEN ARC:
Syndra ---> This almost legendary arch-mage is suffering a withering death from the SoulMonger. DMs can answer, what is a cinematically effective moment for the PCs to greet her and close the tale? -->
...PLAYTESTED CLOSING:
Syndra was on the steps of the temple that resurrected her. All the priests were around her and as the airship lands she greeted them, thanked them, and offered them the reward they were promised. We aimed to make it kind of like the end of Star Wars throne room moment.
OPEN ARC:
Acererak ---> This legendary arch-lich is defeated in his effort to create a new God by the adventurers. The adventure mentions that the Acererak decides to kill the PCs with the most powerful tool he has to wield: time. As an immortal, their lives are a blink in time. He will let them die and haunt their progeny. This is a haunting story moment that would seem a great loss to the story if PCs were deprived of experiencing this realization.
...PLAYTESTED CLOSING:
---> In the calm of the epilogue, Acererak delivered his message of dark vengeance to their dreams months later so the PCs realized that the quest to end Acererak had just begun.
