Caenogenesis

The Gemini Files Book 1

Fiction - Science Fiction
Kindle Edition
Reviewed on 02/16/2026
Buy on Amazon

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    Book Review

Reviewed by Jamie Michele for Readers' Favorite

Tasha He’s Caenogenesis, book one of the science fiction Gemini Files series, is set in the fractured city of Ignis, where a Synthetic weapon known as Project Gemini escapes the laboratory that engineered her and begins moving through the districts under the name Yin. Genetically adaptive and trained for combat, she forms an uneasy alliance with Theopold Kraken, a former gang member navigating the fallout of a failed prison break and mounting state surveillance. As government officials seek to recapture her for military replication, Yin’s body begins to break down due to internal nanobot damage, forcing her to confront the scientist responsible for her design and the buried memories he suppressed. Evidence of a second Synthetic built from the same program shifts the balance of power inside the city’s divided political order, drawing Yin and Kraken deeper into a conflict that threatens to redraw the boundaries of control in Ignis. Each chapter opens with an original character sketch in black and white by the talented Emmeli Markegård.

Tasha He’s Caenogenesis is an ambitious and spectacularly executed novel, in a postwar Ignis, where the titular term “caenogenesis” refers directly to an altered development of inherited patterns, and its application to Yin’s engineered genome. The author's tech is as brilliant as the world-building. Readers are able to deep dive into the aftermath of a 2026 nuclear war, where ocular implants broadcast advertising into citizens’ vision, and the division between Modernist districts and Retro sectors, like Scraptown, is fortified by a wall with biometric checkpoints. Yin is the central force, and we witness her evolving understanding of choice right alongside her. Kraken also appears as a fully realized character in the insurgent network, with a totally believable personal ethic that persists inside insurgent operations and informs his tactical judgments. I love the cinematic settings and landscapes. Scrap towers, a swinging industrial electromagnet, and a storm-darkened sky streaked with particulate ash frame a climactic confrontation. This is an intelligently written introduction to a new series, and I'm excited to see what comes next. Very highly recommended.

Gordan Long

Review of advance copy received from Author

This novel is a classic example of Rebels-in-Dystopia Sci-Fi. It has multi-layered conflict, tightly related to the themes and to the emotions of sympathetic characters.

It starts out with an attractive opening: evocative setting description teasing us with an interesting character puzzle that keeps us reading through those tricky opening pages.

Then we are presented with a second character and a more puzzling enigma. This mystery becomes the conflict of the story, and while it isn’t enough to keep our attention riveted for the time the main character takes to ponder the question, we are already hooked on the premise, so on we go.

The inner conflict is between two extremes. One is the stilted social emotional and linguistic behaviour of the characters with varying degrees of cybernetic enhancement. This clashes with the inner human emotions struggling to emerge. The gradual development of the emotional abilities of the two main characters and the progress of their relationship draws us in and connects us to the rest of the story.

One major theme is the struggle between advanced research and the losing of our humanity. At the highest level of government, the arguments on both sides are logical and persuasive, but in the end only prove that if you want to, you can justify any philosophy.

It all boils down to the question whether humanity should ever reach a point where “Principles were a luxury they could no longer afford.”

This story falls under my frequent complaint that there is just too much magic. The main characters are created with so much hi-tech enhancement that they are almost indestructible. This becomes a hindrance to the writing, because their ability to heal injuries rapidly leads the author to stretch out the battles to the point where they lose their emotional effect on us. The fights are powerful and described in minute detail, but after a while it is difficult to remember who has how many cracked ribs but is soldiering on in spite of the pain.

In general, the writing style is fluid and well edited. The precise nature of the science vocabulary is excellent; what sounds like complicated technobabble is actually understandable to the average reader.

The story ends by tidying up the personal conflicts but leaves philosophic clashes to be explored in the sequel.

A model example of its genre. A long read, but worth it.

Maria Ashford

Review of advance copy received from Author

Caenogenesis is the debut novel by Tasha He, a dystopian sci-fi epic set in Ignis, a city-state after a nuclear war. Book 1 of The Gemini Files, the title may seem a slightly confusing choice at first, but it apparently refers to developmental changes that deviate from ancestral evolution, essentially, abnormal development. I’ll be honest, I had to look that one up (and I thought I had a good vocab). It’s the kind of title that makes more sense the deeper you get into the story. And this is a story that will have no problem holding your attention, throwing the reader right into the action.

This is a smart, character-focused sci-fi novel and an epic adventure that doesn’t take itself too seriously. Yin’s journey from weapon to whatever she’s becoming is beautifully explored, and the world and adventure of the book is immersive to get lost in. If you liked Blade Runner, Never Let Me Go, or The Hunger Games, you’ll probably enjoy this. Just be ready to immediately want book two of The Gemini Files, because this one ends right when things are about to get really interesting.