The second module in the R series of competitive modules put out by the RPGA, the competitive association for ADnD connected to TSR, The Investigation of Hydell is a comparatively little known module but it’s one which has an interesting central conceit.

The party is hired to investigate the origin of these slaves called Slinks which seem to be extremely docile and in endless supply but there is something strange about them. So, it’s an investigation into the origin and nature of these Slinks which will take the party to the dismantling of a trafficking ring.

Eventually and spoilers if you ever intend to play this as a PC, you discover that the Slinks are really animated dead with a permanent illusion spell put on them by the traffickers to appear as human-like docile beings. Mechanically it’s a relatively simple dungeon and lore-wise it isn’t in any particular setting, so you can use it anywhere.