Very fun short adventure! My players want to play Descent into Avernus in the future, and I decided to play this adventure with them to sort of tease the future campaign. We played it in 3 sessions (of less then 4 hours each), with a lot of investigation and mystery going on. It reminds me the Death House from Curse of Strahd for some reason: a well built investigation adventure into a single mysterious location.
We had a blast! My players loved it, specially with the fact that the lore is so interesting.
[5 of 5 Stars!]