This is the second book in Andrew Lane's "Young Sherlock Holmes" series.
This one just didn't appeal to me quite as much as the first book in the series, "Death Cloud". There were points in the book where Holmes and the antagonists appeared to be on a stage of their own, invisible to those who surround them and who could have, and most likely would have, intervened. A shootout on top of a moving train full of passengers and staff doesn't often go completely unacknowledged.
When reading this series, one has to remember that the series is meant to depict Holmes as a teen. As such, the logic and cold detachment that one would expect from Holmes is not yet developed. I feel that what Lane is consciously depicting here are some of the early steps that led to the more familiar Holmes. I did find that hard to keep in mind at times when Lane's Holmes showed a bit more compassion than I felt was beyond the Doyle character.
All-in-all, the story was worth the read. I do like the educational aspect of both of the books so far as Lane attempts to paint a fair but informative view of various historical events.