Timelessly Ours, penned by Roxanne Tully, is an evocative journey through time and emotions that captivates readers with its intricate narrative and heartfelt character exploration. Tully’s ability to weave romance with historical depth makes this novel not merely a love story but a profound exploration of the human condition through different epochs.

The novel centers around Sarah, a modern-day librarian who discovers a mysterious old book that inexplicably transports her back to the 18th-century Antebellum South. This isn't your typical time-slip story; it's fortified with layers of historical accuracies and the harrowing realities of that era, which Tully handles with grace and sensitivity. The crux of the story is Sarah’s poignant romance with William, a plantation owner who is progressive for his time but inevitably shaped by it.

One of Tully's most commendable achievements in Timelessly Ours is her development of Sarah as the protagonist. She's relatable and her struggle to reconcile the mores of her time with the starkly different customs of the 1800s is delineated with authenticity and psychological acumen. It’s fascinating to watch Sarah navigate a world where her modern sensibilities clash with the historical context she's thrust into, not only culturally and socially but emotionally and ethically.

The character of William is equally complex. Tully doesn’t shy away from presenting him as a man of his time, which includes having prejudices and engaging in practices now considered abhorrent. Yet, Tully evolves his character with such finesse, influenced by Sarah’s perspectives and the burgeoning understanding of morality outside the societal norms of his era, that readers are compelled to engage with his transformative journey.

Moreover, the dynamic between Sarah and William is a commendably crafted roller coaster of emotions, filled with moments of tentative affection, profound conflict, and soul-searching dialogue. Their love story, set against the tumultuous and morally complex backdrop of the 1800s, offers a deep dive into issues of duty, love, and individual morality. This keeps the narrative not only engrossing but resonant with anyone familiar with the struggles inherent in loving someone from a different world or worldview.

Timelessly Ours also excels in setting descriptions and atmosphere. Tully’s writing vividly reconstructs the 1800s South in a way that is palpably immersive. From the sprawling plantations to the opulent dresses, the stifling social etiquettes to the sweltering fields, every detail is meticulously crafted to transport the reader back in time. This can be both enchanting and horrifying, especially as Sarah navigates through both the beauty and the brutality of the era.

Another standout aspect is how Tully handles the thematic elements of time travel. The rules and repercussions of Sarah's journey through time are thought-provoking and carefully integrated into the plot. The metaphysical questions posed by time travel—such as fate vs. free will and the impact of small actions—are explored in a manner that adds depth to the narrative without overwhelming it.

However, while Timelessly Ours has many strengths, it occasionally succumbs to the pitfalls of predictability in its plot. Some elements, particularly regarding the resolution of the time-travel conundrum and certain character redemptions, might feel somewhat foreseen for seasoned readers of the genre. Nevertheless, these moments do not significantly detract from the overall enchanting and thought-provoking narrative.

In conclusion, Timelessly Ours by Roxanne Tully is a masterful blend of romance, historical depth, and philosophical inquiry. It provides a moving insight into the complexities of love and morality across time and is a commendable novel for those who seek a love story with profound emotional and intellectual depth. Readers will likely find themselves pondering the intricate connections between past and present long after turning the final page. Tully has indeed crafted a narrative that is as timeless as it is uniquely ours.