Holy moly, this module is AWESOME. 10/10 would run again. My friends asked for a murder mystery one-shot, and so I picked up this one to run alongside Eberron - rising from the last war. The Setup of the module is impeccable, the character motivations are great, and I like everything about it. I talked a lot with the characters before hand and they came up with their motivations and such and such a web of deceit and lies as you've never seen before was weaved before my very eyes. I ran this twice and both times the results were completely interesting and unique.
I tweaked a few things (better for 3rd level then 6th level characters, put it on an airship instead of a train), but that's just DM discretion stuff. The core of this module is some really good material and fodder for making an amazing story.
[5 of 5 Stars!]