Babble water
The party comes upon a small stream that has a strange magical glitter about it. While it tastes like normal water, it bestows upon the drinker the ability to understand and speak any language for 1 hour. The water can be collected and will maintain its magical properties. However, taking too much of it may anger the fey responsible. Nearby animals can all talk with the players, and may have useful information.
The creeping fire
The party comes upon a slow moving flow of magma. It has already burned and crushed its way through the nearby wilderness, and is now approaching a village. The locals are trying to stop the flow. The party can lend a hand in digging trenches and raising earthern walls, to earn the goodwill of the locals, who will gladly invite the players to their town and offer food and lodging.
Stopping the lava flow requires a group check for strength (athletics) DC 16 and takes several hours. A succesful intelligence (nature) check DC 12 can inform them where best to dig their trenches, giving them advantage on the strength check. Magic can also be used to create barriers, which lowers the strength DC to 14.
Alternatively, if the players ignore the threat, the village will be destroyed by the flow the next day. Abandoning the locals in their hour of need may anger the gods if any of the party members are good aligned and pious, and bring them bad fortune. They take disadvantage on all checks for a week.
The source of the magma is a fissure in the earth. The party can follow the path of destruction to reach the source. The magma is still warm, but hard enough to stand on. The DM may rule that the fissure is the entrance to a mini dungeon, or that it is too small to crawl inside. The party can use magic or other means to seal the fissure completely, or journey inside to find the cause.
Harsh interrogations
The party can hear calls for help coming from a nearby bridge. Two men are dangling a young man from the bridge into the stream, asking him where he took the wares. The young man, named Harrold, denies knowing what they are talking about. Harrold was enchanted by a wizard, to steal wares from a local nobleman. The two men work for the nobleman, but Harrold truthfully does not remember a thing. The men know Harrold is involved in the theft, as a witness saw him during the night. Harrold has no recollection of any of it.
The players can try a charisma (diplomacy) check DC 10 to get the men to stop their interrogations. Threats of calling the guards do not impress the thugs, although any threat of armed conflict may get them to back off upon a succesful charisma (intimidation) check DC 14.
The players can also call for the guards. However, as soon as the thugs namedrop their employer, the guards will back off and allow them to continue their interrogations of Harrold.
The party can also offer to interrogate the young man themselves. Truthfully, the two thugs are getting tired of dunking Harrold into the river, and feel like they are getting nowhere. So they'll be eager to let someone else take over. Magical interrogation can get Harrold to spill the beans on his nightly activities, as can a dispel magic. Harrold is still enchanted, and a spell clouds his mind. Once the magic is lifted, Harrold can retrace his steps back to the wizard, where they find all of the stolen wares. The wizard has some beef with the nobleman, to be decided by the DM. This could be another plothook if the DM so chooses.