Secret of Ruby Village

From the introduction:

Below the small pass-through town of Ruby Village, lies a secret. Long ago, the Ruby Rogues once made this village a command center and training facility for new initiates, though all that remains now are rumors. The existing thieves' guild has always kept someone at the local inn to guard past secrets, passing down information to select few. Hidden doors offer passage down into the long-forgotten lair. Two are located on the grounds of the inn, while one is lost with the ruins of an old structure, long overgrown. The area is also a residence for underground creatures. Perhaps the party comes looking for the area's secrets, or perhaps they stumble upon one of the ways down into the darkness.