The novel “The Causal Angel” by Hannu Rajaniemi was published for the first time in 2014. It’s the sequel to “The Fractal Prince“.

Jean Flambeur and Mieli are separated after the attack they suffered. The consequence is that each of them has to face a series of dangers on their own and that at a time when various forces are preparing for a war as of an unprecedented scale in the solar system.

For Mieli, the dangers derive from what she has in her head, information that could be precious in the upcoming war and that someone would like to extract at any cost. Jean Flambeur wants to save Mieli but at the same time has to face other complications.

In this third novel in the Jean le Flambeur trilogy there’s the continuation of this thief’s adventures set in a future when post-humans have colonized the solar system and use highly advanced technologies. The events immediately follow those of “The Fractal Prince” and are partly connected to them so you need to have already read the previous novels, also to get to know characters and setting.

In addition to the protagonists Jean le Flambeur and Mieli, other characters come back from the previous novels, in particular Josephine Pellegrini and Matjek Chen. However, this trilogy is set in a fictional universe where technology has made the concept of identity vague and shifting and this strongly influences the characters’ development.

Jean le Flambeur’s case is the perfect example of Hannu Rajaniemi’s way to handle the characters: we could say that there’s a basic Jean le Flambeur who tells his story in the first person but there are other versions or simply the protagonist uses a disguise and their story is told in the third person.

“The Causal Angel” is in many ways the story of Mieli, the warrior from the Oort Cloud whose story ends up being tied to Jean le Flambeur’s. Various flashbacks revealed events from her past already in “The Fractal Prince” and in the third novel the reader discovers more about her and other people close to her.

In general, in “The Causal Angel” there are a lot of new information on the past of the solar system and the factions preparing for an unprecedented war. All this in the style already seen in previous novels, with extensive use of terms invented by Hannu Rajaniemi that don’t have a precise explanation.

In essence, this final book of the trilogy is also in some respects a roller coaster where the reader has to let go and enjoy the ride just guessing the general sense of the concepts without paying attention to details. On the other hand, in a fictional universe in which everything is fluid, details are not fixed so trying to grasp them is pointless.

In a work where style has a remarkable importance, so much so that it can be considered part of the substance, the problem is that sometimes characters and plot get overshadowed. In “The Causal Angel” more than ever the protagonists face serious dangers and in general the events are supposed to be intense but honestly I didn’t have these feelings exactly because the style is sometimes overwhelming.

If you read the previous novels, you already know that this trilogy is not suitable for those who look for precise plots and/or a classic character development. This doesn’t mean that these elements are absent but that they’re developed in the style that Hannu Rajaniemi used in this trilogy. The result is original, evocative, and intriguing in very unconventional ways.

“The Causal Angel” is, in various ways, the culmination of the whole trilogy with developments based elements and characters included in the three novels. For this reason and for the overall complexity, the best thing is to read the whole trilogy in a fairly short period of time so that you don’t have to start another immersion in that truly unique fictional universe at the beginning of each novel.

For its characteristics, “The Causal Angel” is not a novel that everyone can like. If you find Hannu Rajaniemi’s style and the type of story he developed intriguing, you will surely like it and in this case I recommend reading the whole Jean le Flambeur trilogy.