With This Mask, authored by Vera Black, is a compelling narrative woven around themes of identity, secrets, and redemption, set against the backdrop of a Victorian-era society teeming with societal expectations and clandestine operations. This novel, rich in historical ambiance and complex characterization, invites readers into a deeply immersive world where everyone wears a mask, both literally and metaphorically.

The story centers around Eleanor Sutton, a young and astute woman born into a family of high societal standing. From a young age, Eleanor has been taught the art of subterfuge—a necessity in a world where appearances both uphold and betray one's status. The element of physical masks, used by characters during opulent societal balls, serves as a poignant metaphor throughout the book, reflecting the multifaceted disguises each character embodies in their daily interactions.

Black's narrative prowess shines particularly in her ability to weave intricate plot lines that engage and surprise. The reader is drawn into Eleanor's internal and external conflicts as she navigates through a series of mysteries centered on the sudden death of a prominent lord during a masked ball. As Eleanor delves deeper into the heart of this enigma, the façade of the aristocracy crumbles, revealing layers of deceit that test her beliefs and moral values.

The author's mastery is also evident in her rich, atmospheric settings that perfectly capture the essence of Victorian society. From the lush, detailed descriptions of the decadent ballrooms with their gilded decorations and flickering candlelight to the somber, fog-laden streets of London, the setting becomes almost a character in itself, pivotal to the development of the story's mood and tone.

Characterization is another area where With This Mask excels. Eleanor, as the protagonist, is portrayed with a depth that makes her both relatable and enigmatic. Her growth throughout the narrative, from a compliant daughter to a formidable detective in her own right, is crafted with nuance and credibility. The secondary characters are no less compelling. From the charming yet secretive Thomas Gale to the stern and mysterious governess Mrs. Whitaker, each character is well fleshed out, contributing to the tangled web of intrigue that propels the plot forward.

Black also deftly handles themes of societal expectation and the limitations placed particularly on women during the era. Eleanor's struggle against these societal norms, her desire to be more than just a decorative object in a high-stakes societal game, is particularly well-articulated. This feminist undertone serves not only as a commentary on the past but also resonates with the ongoing contemporary discourse about gender roles and equality. Yet, the novel never feels preachy or didactic. Instead, these themes are naturally interlaced with the story, enriching the narrative without overshadowing the entertainment value.

The pace of the book is meticulously controlled. Starting with a slower, detailed exposition that lays down the groundwork for both setting and character, it picks up momentum as the mysteries begin to unfold. The tension is skillfully built up, climaxing in a series of revelations that tie together the intricate plot threads in a satisfying conclusion. However, this crescendo is occasionally dampened by moments where the descriptive passages, although beautifully written, stall the narrative progression slightly.

Additionally, the dialogue in With This Mask is another aspect worth noting. It captures the diction and formality of the period with a finesse that adds authenticity to the interactions. The clever use of language not only differentiates between characters from various societal standings but also adds layers to their personal disguises.

On a critical note, while the plot is generally tight, there are instances where the myriad subplots threaten to overwhelm the main narrative. Certain plot lines, particularly in the middle section of the book, could have been streamlined or woven more tightly into the main storyline. Nevertheless, these are minor flaws in what is otherwise a beautifully crafted novel.

In conclusion, With This Mask by Vera Black is an exquisite dip into Victorian mystery and intrigue, filled with compelling characters, rich settings, and a well-constructed plot. It goes beyond mere mystery to explore the depths of human nature and the societal masks we wear. For fans of historical fiction and mystery alike, this novel proves to be both entertaining and thought-provoking, making it a recommended read for those intrigued by literature that combines depth with entertainment.