The Artificer's Knot is a standalone gaslamp fantasy novel, written by Eric Lewis, and set in the same world as his Heron Kings series; putting the focus on Randyll Tephius, an artificer that was expelled from the University as his thesis on alternative energy sources challenges the Vril monopoly that is controlled by the Alchemists. In disgrace, he's surviving in the streets until he's rescued by the mob boss Gouger Nebb, who is looking for a way to get out of this life.

Slowly gaining Nebb's trust, Ran starts climbing in the gang hierarchy due to his inventive and ability to do other tasks people in the gang are unable. Finally, Nebb decides to fund him to create an oil plant, thinking on it as his retirement plant; however, even if Ran wasn't intending to become a mob, soon he finds that his efforts are received with sabotage from other gangs and from the own Alchemists that destroyed his life. Ran just wanted to recover his old life and prestige, but he will find himself in the middle of a war between the powers that control the city.

With this proposal, Lewis masterfully weaves a classical mafia story with a subplot about the energy sources, without hiding the influences from classics of the genre, such as The Godfather and Peaky Blinders, even including some easter eggs that are a delight to read, paying an homage to it. A dirty war on the city that will end involving the own law enforcement corps and that will reach the high spheres of the power; all in a well-paced plot that is not shy about portraying the darkest aspects of it.

Randyll is an interesting character, a bit arrogant due to his origins, but who has been hit hard by life; ascending from the ground will require him to embrace the worst aspects of humanity, even if he wasn't ready for the mob life. We also have the opportunity to see how he has a soft spot for those he appreciates; he's not a bad man, but one that life has not treated well. 
While secondary characters are not as well developed, we spend enough time with many of them to slowly develop a bond with them; especially with Nebb. He is a gang boss, but it's not cruel; just fair and do what it is needed to maintain the status quo (I would say that Thomas Shelby could be a good parallelism).

The setting helps the story, a country that has experienced a fast industrial revolution with all based in the Vril, a product that is tightly controlled by the Alchemists, becoming the source of their power. New energy sources are threatening it, and that's why they sabotage anybody that might introduce alternatives to Vril.

In definitive, The Artificer's Knot is a great novel, a story about a man that descends to the crime world in order to finally climb out of the pit; if you like classic gang/mafia stories, you will for sure enjoy it. I'm curious to read more instalments in the same world, as it has a ton of potential.