Below is the complete list of Caroline Peckham’s and Susanne Valenti‘s Sins of the Zodiac books in order. For this series, the chronological reading order is the same as the order of publication.
Publication Order of Sins of the Zodiac Books
with Susanne Valenti
- Never Keep (2024)
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Never Keep was published in 2024 and is listed as book #1 in the Sins of the Zodiac series. - Echo Fort (2025)
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Published in 2025, Echo Fort is listed as book #2 in the Sins of the Zodiac series. - Cinder Vale (2026)
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Cinder Vale is a 2026 release and appears as book #3 in the Sins of the Zodiac series. - Oracle Bay (2027)
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In the Sins of the Zodiac series, Oracle Bay is book #4 and was published in 2027.
About Sins of the Zodiac
Caroline Peckham and Susanne Valenti’s Sins of the Zodiac series is a romantasy spin-off set in the same wider universe as Zodiac Academy, but it moves into a different corner of Solaria with its own conflict, cast, and emotional stakes. The series begins with Never Keep, continues with Echo Fort, and carries forward through later planned installments such as Cinder Vale and Oracle Bay. Rather than simply repeating the academy structure of the Vega twins’ story, Sins of the Zodiac opens out into the Waning Lands, a harsher setting shaped by war, divided kingdoms, dangerous magic, and old sins that refuse to stay buried.
The central figures are Everest and Vesper, two characters caught inside the Endless War, a conflict that gives the series a more openly epic fantasy shape than some of the authors’ earlier Solaria books. Zodiac Academy is driven by school politics, fae hierarchy, elemental power, and royal inheritance. Ruthless Boys of the Zodiac leans into murder mystery, academy danger, and reverse-harem romance. Darkmore Penitentiary is built around confinement, prison survival, and forbidden bonds. Sins of the Zodiac feels broader and more war-torn from the beginning, with the romance unfolding against a landscape where entire territories, loyalties, and histories are unstable.
Never Keep establishes the new branch by introducing the world beyond the more familiar Solarian settings. The title itself suggests one of the series’ main ideas: what people try to hold, hide, claim, or protect may be exactly what destroys them. Peckham and Valenti often write characters who are driven by fierce desire and damaged loyalty, and that pattern fits naturally here. Everest and Vesper are not placed into a gentle fantasy romance where love arrives cleanly. Their story grows inside conflict, danger, and distrust, with the emotional pull sharpened by the fact that the world around them is already broken.
Echo Fort deepens the series’ mythology and conflict, expanding the consequences of the war and the characters’ choices. The “fort” imagery suits the series well because Sins of the Zodiac is interested in defenses: the walls kingdoms build, the secrets people hide behind, and the emotional barriers that make trust almost as dangerous as betrayal. As the story progresses, the romance and the larger fantasy plot become harder to separate. Desire, survival, strategy, and power all move together.
The series also matters because it shows Peckham and Valenti continuing to grow the Solaria universe after the main Zodiac Academy arc. Readers familiar with their earlier books will recognize the intensity: sharp romantic tension, morally complicated characters, brutal reversals, and a willingness to let love develop through conflict rather than comfort. At the same time, Sins of the Zodiac has its own identity. It is not just another academy romance or a side story built around familiar characters. It is a new romantasy arc using Solaria’s larger magical framework to explore war, fate, enemies, and the cost of power.
Sins of the Zodiac is best understood as an epic, enemies-to-lovers romantasy branch of the authors’ wider world. Its appeal lies in the combination of dangerous magic, divided lands, fierce emotional conflict, and characters who are forced to decide whether love is a weakness, a weapon, or the only thing strong enough to survive the war around them.