Ashley O'Donovan's What Courses Through Her Blood is a riveting conclusion to the saga that began with What Lies Beyond the Realms. This final installment in the series is a masterful blend of fantasy, romance, and the eternal struggle between light and darkness. O'Donovan has crafted a narrative that is both epic in scope and intimate in its exploration of personal sacrifice and the burdens of power.

The story picks up with Lyra, our formidable protagonist, who is fresh off a significant victory. However, the respite is short-lived as new threats loom on the horizon. The realms are teetering on the brink of collapse, and Lyra finds herself at the center of a storm that threatens to consume everything she holds dear. The stakes are higher than ever, and O'Donovan does not shy away from exploring the complexities of leadership and the heavy toll it takes on those who bear its mantle.

One of the most compelling aspects of this book is its exploration of the duality of power. Lyra's dark magic is both her greatest asset and her most dangerous liability. O'Donovan skillfully portrays the internal conflict that arises from wielding such power. Lyra's struggle to control her magic is a metaphor for the broader theme of balance—between light and darkness, love and duty, self and others. This theme resonates throughout the narrative, providing a rich tapestry of moral and ethical dilemmas that challenge not only Lyra but also the reader.

The character development in What Courses Through Her Blood is particularly noteworthy. Lyra is a well-rounded character whose growth is both believable and inspiring. Her journey from a young woman burdened by her powers to a leader who embraces her destiny is portrayed with nuance and depth. The supporting characters, particularly Colton and Nyx, are equally well-developed. The love triangle between Lyra, Colton, and Nyx adds an emotional layer to the story, forcing Lyra to make a heart-wrenching decision that could alter the fate of the realms. O'Donovan handles this dynamic with sensitivity, ensuring that it enhances rather than detracts from the central narrative.

O'Donovan's world-building is another highlight of the book. The realms of Eguina are vividly depicted, with each setting offering a unique backdrop that enriches the story. The author's attention to detail is evident in the lush descriptions of landscapes, the intricacies of magical systems, and the cultural nuances of the different realms. This immersive world-building is reminiscent of the works of authors like Sarah J. Maas and Leigh Bardugo, who similarly excel in creating expansive and engaging fantasy worlds.

In terms of pacing, the book maintains a steady rhythm that keeps the reader engaged from start to finish. The action sequences are well-executed, providing a sense of urgency and tension that propels the narrative forward. At the same time, O'Donovan allows for quieter moments of introspection and character development, ensuring that the story remains balanced and emotionally resonant.

One of the book's most significant achievements is its ability to weave together multiple themes and plotlines into a cohesive and satisfying conclusion. The themes of sacrifice, redemption, and the transformative power of love are interwoven with the overarching narrative of a world on the brink of destruction. O'Donovan's ability to balance these elements is a testament to her skill as a storyteller.

Comparatively, What Courses Through Her Blood stands out in the crowded field of fantasy literature. While it shares thematic similarities with series like A Court of Thorns and Roses by Sarah J. Maas and Shadow and Bone by Leigh Bardugo, O'Donovan's work is distinguished by its focus on the internal struggles of its protagonist and the moral complexities of power. The book's emphasis on personal growth and the consequences of one's choices adds a layer of depth that is both thought-provoking and emotionally impactful.

In conclusion, What Courses Through Her Blood is a fitting end to a remarkable series. Ashley O'Donovan has delivered a story that is as much about the journey of its characters as it is about the fate of the realms they inhabit. With its compelling characters, intricate world-building, and exploration of profound themes, this book is a must-read for fans of fantasy literature. It is a testament to the enduring power of storytelling and the indomitable spirit of those who dare to wield it.

For readers seeking a tale of adventure, love, and the eternal struggle between light and darkness, What Courses Through Her Blood offers a captivating and satisfying experience. It is a story that will linger in the mind long after the final page is turned, a testament to the enduring power of hope and the resilience of the human spirit.