... is not, it should be noted, the easiest book with which to join the series ... Goss is invested in playing with the tropes of late-19th and early-20th century pulp, and with their characters. (And in playing with narrative: the construction of the novel as a told story, aware of itself as a construct.) Her villains straddle the middle ground between the cliché and the complex ... The size of the cast means the reader spends less time with each individual character than in previous volumes. While the characters—at least the ones we spend any amount of time with—remain compelling, the number of people who share the limelight means that the overarching plot has to carry the weight of keeping the reader invested in the story ... While some characters question whether 'saving the British empire' is in fact something worth doing, the narrative itself ends up reinforcing the idea of a British empire, headed by the elderly Victoria Regina, as a normative, even positive thing. The romance of empire is a heady thing, but in a novel that successfully interrogates—while playing with—many other tropes of the pulps that it’s re-envisioning for the modern age, the eucatastrophic restoration of the status quo feels a little… off ... On the whole, while I enjoyed reading The Sinister Mystery of the Mesmerizing Girl, and while it’s an entertaining instalment in the series, it’s less well-paced and weaker than its predecessors. Goss doesn’t quite live up to the high standards she’s previously set here.

The first two books' problems are still present here, with too much exposition and largely pointless commentary from the characters themselves. But the tone is lighter and the prose shows marked improvement, making those issues far less noticeable. The villains are more compelling, the plot twists land well, and the literary-character mashups don’t feel so forced ... An uneven series ends on a high note.

... the pace at the book’s outset is a bit sluggish and confused. A quarter of the book passes before it becomes clear that Alice and the others have been kidnapped as part of a nefarious plot that reaches the highest political strata of the British Empire ... The characters remain delightful but develop relatively little. Topicality and tenacity, in the person of the self-effacing but determined Alice, bring the series satisfyingly home. Fans of the first two novels will find this one a solid capstone.