A pretty good adventures with a few flaws.

I ran this adventure using the Genesys RPG system and it worked very well. I also removed Steel-Eye Dixon as a character and just made the characters themselves the private eyes. This helped a lot with motiviating the characters, but I'll admit that only works because I ran it as a one-shot. Overall, I liked the adventure a lot. The tone is spot-on and the plot is interesting. However there were a handful of things that I think could be better.

SPOILER WARNING:

1. There is very little reason why the characters would know to go to the shrine of Onatar. The only clue is the manufacturer of the amulets, and he doesn't actually know anything about the cult's hideout. All he knows is that it is in Fallen. The provided option of 'just asking around for X amount of time while spending Y amount of gold' is a great backup, but the way the adventure is written, that is pretty much the only way to find the shrine. The third option of getting a letter from Delthana is a little too heavy handed for my taste. I resolved this by adding a broken off Icon of Onatar to the appartement of the third murder victim. That way the characters can figure out where such shrines are located, and then narrow it down to Fallen after talking to the jeweler. Another option would be to just move the hideout out of Fallen into another poorish Sharn neighbourhood. It would lose some of the Sharn specific flavour, but it would probably reinforce the Noir feeling a little bit.

2. I found it a little difficult to justify why Kystine didn't simply run after stealing the bonds. It can be justified if the timing of the characters arrival is on point, but that might be hard to sell. Especially if the characters took hours if not days to get to the shrine. I can see that Kystine wants to be found while being held captive to have an alibi, but Kystine tying herself up in the temple would raise a few eyebrows.

3. The first part of the adventure, the investigation of the crime scenes, can be quite repetitive. That might not be to everyone's taste.

4. Considering how far apart the crime scenes are, I found it difficult to believe that the city watch would immediately identify them as connected. My group was very suspicious about that. I had to provide some meta information and tell them that there is no conspiracy by the city watch.

That being said, I was very happy with the adventure.

Taking a very Noir feel to the whole Eberron world, the City of Blood story allows you to jump right from the Eberron given story into this crime scene story. I wish that there were actual crime scenes included along with the pictures of the individuals found, but through some googling, it wasn't that hard. The one thing I wish that it went over a little more was some criteria for a certain tool, SPOILERS the dagger. When it changes the person into the other, I added that the amulet also had to be used in conjunction to make sure that this was not a broken mechanic. Other than that, a great mystery that if you put on some Noir jazz will have all your players thinking they are in Chicago or some other noir movie landscape.

Great for a starting adventure or one in the middle of other business in Eberron. Skill-focused characters shine in the investigations, and combat characters have 2-3 encounters as well. Mix it up to suit your party. This adventure takes them from the richest to the poorest districts and has clever clues for your players to find (they're not meant to be well hidden; the chase is part of the fun!). My players came into this adventure when they needed allies, and Steel-Eye Dixon is a good one. If they play their cards right, your players will even get recurring villains and the whiff of an artifact that wouldn't be out of place in Wildemount. tl;dr A+ Eberron murder mystery that adds to any campaign

It's a good adventure, took my group two sessions but can definitely take one. It leans all the way into the investigation side of it where there are normally only two fights in the adventure (my players only encountered one of them). there's an optional fight in it in case you really want one, it doesn't add much. It's an adventure about looking for clues and putting them together and is strongest at that, you don't even meet nor know the existance of the bbeg until the end. Would also love if it included a hi-rez version of the hideout map.