Concept

D&D

So I'm doing the RPG Adventure Writer course in July (I'm about five days behind, thank you very much) and it costs money if you want to do something other than D&D5E and DM's Guild, so that's what I'm doing.

The concept is, uh, weird, but it might make a nice one-shot.

You're a group of first-level characters and you've just come back from the wars or hanging around with military service; the point is, you're back or conceivably new to the area.

And a tavern owner approaches you; the tavern owner is definitely just back, and he has discovered what I'm about to tell you, and doesn't know where to turn. His tavern has been overrun with Mysterious Strangers, who have sent everyone of an adventuring nature off to far-off lands. He's got no regulars, his bar staff have disappeared and replaced with simpletons, and they won't let him in.

Various avenues of investigation, but the PCs eventually learn that the Mysterious Strangers are members of a hive organism and they've taken over the tavern. Deep under the tavern, the queen is churning out Mysterious Strangers, workers (who look like barmaids), and owls (drones). Deeper down there are warriors, wizard-like things, and so on. They look like people, but they're something else....

Having found this out, the PCs must go in, possibly to rescue the tavern keeper and his family.