I wrote at length in the product discussion section but wanted to post here as well.
This is a brilliant scenario. It is incredibly challenging, and I think we could have done with 8 hours of play and still not fully plumbed the depth of the potential interactions within the scenario, but it was an incredibly rewarding experience to run this for my players. Watching them overcome the challenges, pick up on the clues and come up with some clutch plays was the most fun I've had as a GM for a good long while.
This scenario requires a LOT of preparation on the part of the GM - not just in the mechanics, but how you will plant the seeds for future encounters with the players. I ran low-tier for a mixed group (7, 8, 8, 9, 9, 9), and while it was challenging (sometimes painfully, frustratingly so for the players, I think), seeing them persevere and come through mostly unscathed (no one died, anyway!) made me so very very happy. Closed out a con with this, one in which I ended up killing two other characters, but a well-prepared party that is used to the Osirion-style delves can handle this well.
This is NOT a scenario for introductory-level players. I would strongly recommend playing the other Scarab Sage scenarios first - not only to get the most out of the story but also to have a number of opportunities to understand what sort of dangers you might face.
Thanks again to the author for an awesome experience. More like this, please.
