This is (sorry for the pun) a dreamy slow-burner of a novel. The prose is lyrical and intensely descriptive, but also provides a powerful picture of the novel's main character, Agnes Trussel, as she comes to terms with the crisis she experiences.
Agnes is a fascinating and clear-sighted woman, with a touching innocence about the people she encounters. Her quiet strength of mind is also a driving factor of her story. Not a great deal happens, but the key events which do take place are absolutely crucial and a turning point for Agnes' life. The historical settings are keenly felt and, indeed, London becomes a character in its own right within the book.
I very much enjoyed the relationship of pupil and teacher (and, later and subtly, more) between Agnes and the firework-maker, Blacklock, who takes her in and teaches her his trade. Perhaps the various methods of creating fireworks might be - for me - rather too much depicted in the story and I didn't need to know that level of information, but Agnes remains strong enough to carry me through the occasional plot weakness.
The final chapters are very powerful indeed, and I appreciated the open-ended and ultimately hopeful conclusion. A novel to savour.
Verdict: 4 stars: a worthwhile slow-burner read