An excellently written and constructed adventure. I really like that it contains notes on how to incorporate it into Descent into Avernus or run it as a stand alone. It's fairly combat-heavy but rewards stalwart groups with XP, gold, and magic. One aspect I like is that it's suitably creepy and even a bit scary, which makes it a seamless addition or replacement for official content.
Frankly, I think this is as good (or even better) than some of the content in the official adventure. I plan on using it with my group. Highly recommended.
[5 of 5 Stars!]