Goblins of Rough Top Mountain (5E)

From publisher blurb:

This adventure is for 4-6 heroes of 1st or 2nd level, for a one-shot adventure for 5th Edition. (Though this may take 1-2 sessions to complete).

For decades the humans and goblins who inhabit Rough Top Mountain have lived in peace, with each side keeping its distance respectfully but serving to help each other with the goblins mining ore in the mountains, and the humans selling the products made from it. There have only ever been a few minor skirmishes. Something has changed and the heroes are brought in by a group of rangers to put a stop to the goblin attacks on the town. But not all is as it seems.