From publisher blurb:
One should never meddle with interplanar portals without knowing what one is doing. Unless, of course, you find yourself stranded on an alien planet littered with portals, of course. The party happens to be in this exact situation, trapped on Exodus with the portal they walked through closed behind them. Through careful magical experimentation, or perhaps trial and error, they can work to solve the puzzle of the gateway and re-establish a link back to their home!
This adventure is a sidequest in the Chronicle of the Gatekeepers Journey, and includes:
Details on how precisely things can go wrong when messing with unstable interplanetary gateways
An introduction to the prymidians, brilliant linguists and scholars
A new racial implant for prymidians, the linguistic tongue