Stephanie Patrick is drawn back into the dangerous world of espionage when a new threat emerges from China. Still bound by her obligations to Magenta House and attempting a normal civilian life in London, Stephanie finds herself entangled in a complex operation involving the clandestine movement of scientific and weapons secrets. Her personal involvement with one of the victims of this trade leads her to make a critical error, unleashing consequences that test her formidable skills and expertise to their limits.

Gemini is lauded as a gripping and intelligent thriller, marking a welcome return for its unique heroine, Stephanie Patrick. The novel is recognized as a compelling sequel to Chameleon, appealing to fans of authors like Robert Harris and Michael Connelly. Critics highlight Burnell's ability to craft a narrative that is both suspenseful and intellectually engaging. The book is noted for its intricate plot and the challenging circumstances faced by its protagonist, even with her considerable skills.