From "Adventure Summary and Background:"
This is easily the simplest set-up ever. The characters are not together at the beginning of the adventure. Each PC is independently going to Grand Coryan, acting as a courier for an important message. What the message is and who it’s going to is actually beside the point, however, as what seemed like it would be a typical journey by way of the Gates of Anshar takes a drastic turn for the unexpected.
This module should illustrate why important people rarely use the Gates of Anshar except in the direst of circumstances. It also gives the PCs an opportunity to discover one of the long-lost secrets of Arcanis – a secret that, at least for some, might very well change the way they view the world. Of course, first they have to survive the experience of discovery…