Once upon a time, Wizards of the Coast had a big list of free adventures by professional game designers that, sadly, was nixed as the company went through some big changes switching to 4th and then eventually 5th edition.
Thankfully, the Internet never forgets, though, and the Wayback Machine still has snapshots of that page where many of the download links still actually work! The full list can be found here.
One of my personal favorites from that list was A Question of Ethics by Monte Cook, in which the party discovers a group of adventurers planning on unleashing a plague on a nearby tribe of stone giants.
The group has to grapple with some moral choices and then decide whether to side with the giants, who might be a threat in the future, or the adventurers, who are committing a war crime against giants who have done nothing wrong ... yet.