While your group is out wandering the supposed wilds of [Region Name], they find a small elderly halfling struggling to drag a sheet of wood into a clearing.
If your party offers to help him, he will introduce himself as Neville Armstrong and, yes, he will openly comment on the irony of his name given the situation you found him in. He will assure the party that he was much stronger for his size back in his youth; in fact, the only thing that hasn’t gotten weaker with age is his capacity to dream big. He will explain that he longs to reach the stars and step foot on one of the twelve moons (or however many moons your homebrew world might have).
When your party reaches the clearing, they will see Armstrong’s house. It’s a traditional halfling dwelling, complete with circular door and stone-stacked walls. The only thing that’s different is the yard out front. In addition to small vegetable gardens and other natural sights befitting of a halfling home, there is an assortment of half-finished machines and wacky contraptions. Some have clear purposes (like a large wooden machine with an arm and axe, intended to automate cutting firewood), while others look more like wood/metal garden art with no discernible purpose.
Armstrong will show you his current project by whisking away a linen tarp: a small, largely wooden, rocket-ship-like device outfitted with 3 large bottles as its “thrusters.” Inside these large bottles, your party can see swirling wind, occasionally forming angry faces. The halfling will explain that he has procured 3 young air elementals in magical “unbreakable” bottles. He intends to harness their wind magic to defy gravity and propel himself skyward in his vessel.
In fact, he only needs to attach this last piece of wood sheeting to the side of the rocket before his contraption is ready. He will ask your party if they’re ready to see “history in the making.”
Once Armstrong has hammered and attached the final piece of wood, he will be prepared to take flight. He will shuffle off into his house for a moment and emerge carrying a scroll. Armstrong will tell your party that he has spent his entire life-savings on the bottled air elementals and this particular spell scroll. However, there is no buyer’s remorse here; he is completely starry-eyed and dreaming of his coming greatness.
If you have a Bard in your group, Armstrong will encourage him/her to tell the story of his extraterrestrial adventure to hopefully inspire the next generation of space explorers. He might even complain a little about how there are all these different “planes of reality” that people want to explore, but why? There is still so much wonder and strangeness in this plane that deserves our attention.
After waxing poetic for a minute, Armstrong will unroll the scroll and cast “True Polymorph” from it, changing himself into a halfling-sized mechanical construct (thereby allowing him to survive on the moon with its lack of oxygen and pressure changes).
Armstrong will not be able to speak in his new polymorphed form, but he will make a bow to your party before entering the vessel and pulling a lever. At this motion, a device will agitate the air elementals, and they will begin swirling angrily in their bottles. Then, surprisingly, the ship will blast wind magic beneath it and propel itself directly skyward toward the moon perfectly hanging overhead.
At first, everything will look very promising. Then, a large bird will come flying from the neighboring woods and thud into the side of the small vessel, tilting it in the sky about 15 degrees and irreparably altering its course. The vessel will arc through the sky before diving down into some trees in the distance. There will be the clear sound of a crash, and your party will see more birds take off in flight from the crash site about 100 feet away.
The Impact Site
If your party is truly callous, they may just leave the side quest at that and carry on with whatever they were doing before. However, if they choose to head into the forests to investigate the impact site, they will be faced with another challenge.
Entering into this new clearing, your party will see the small ship’s wreckage scattered about. Armstrong will also be there, alive, but unconscious and having reverted back to his halfling form after taking damage as the polymorphed construct.
Even more problematic: the air elementals will no longer be contained in their bottles. At the sight of the approaching party, the three elementals, now freed, will merge into one singular large air elemental that the party will need to face in combat (or three if your party is strong enough).
After defeating the elemental(s), your party will be able to revive the halfling. If your party is ill-equipped with healing spells or items, they can carry him back to his home; inside his home, they will find a couple of potions and other medicinal herbs.
Upon awakening, Armstrong will ask you if he was successful. You can choose to give him whatever answer you’d like. If you tell him that, yes, he went up to the moon but then returned, he will be thrilled but lament that he doesn’t remember his experiences while polymorphed. If you tell him the truth, he will be disappointed, but grateful for your help, and he will tell you, as the next generation, to achieve what he wasn’t able to.
Either way, he will reward your party with another one of his special devices. He calls it the “Star Shooter.” This device is literally a just light crossbow made of a very dark wood, but it is adorned with tiny pieces of polished metal so that it looks like a starry night sky.
Any bolt fired from this crossbow (Armstrong will give you 10 to start with) will deal 1d8 damage to a target at 80/320 feet. Additionally, at the cost of the bolt disintegrating, the arrow will deal 1d8 radiant damage to anything within 5 feet of the target.