Sherlock Holmes is a young man whose family is fragmented and who is staying with a slightly mysterious uncle and aunt while being tutored by an American detective Amyus Crowe. He is intelligent and inquisitive, especially interested in the way in which things work.

When Amyus and Mycroft, Sherlock’s older brother, become aware of the escape of John Wilkes Booth, whose assassination of President Lincoln has made him a rallying-point for a possible Confederate army, Sherlock takes matters into his own hands and tracks down where Booth and his accomplices are staying. With Amyus and Virginia (Amyus’ daughter) he follows the gang to New York. Imprisoned, they break free and carry the news of a Confederate army massing near the Canadian border, but Sherlock feels impelled to act again when it appears that the American president will show no mercy in eliminating this threat to the Union.

The Sherlock Holmes phenomenon has always attracted its share of spin-off stories, so it’s far from a surprise to find a Young Sherlock Holmes series on the shelves. This is the second episode. I don’t know how different the first one is, although there are some background points which are referred to here which presumably either occur or are explained in the first book. The book runs at two levels: at one level is the particular story of John Wilkes Booth, assassin of Lincoln, physically and mentally scarred in a fire caused by a shootout, plausible rallying-point for the Confederate cause, and the man who’s masterminding the operation invade Canada and then to attack the United States. At the other level is the partly-told backstory of the Holmes family, Sherlock’s friendship with Amyus and Virginia, and the mysterious Mrs Eglantine – ostensibly his Aunt’s housekeeper, but evidently something more sinister. The stories run on separate tracks, only occasionally touching.

Overall, the story is fairly engaging, if fairly lightweight. My principal complaint is, as is so often the case, of a wasted opportunity. Arthur Conan Doyle’s Sherlock Holmes stories are a phenomenon of popular literature. If you’re writing while leaning on the shoulders of giants, you’ve really got to make sure that the result is worth it. And you’ve really got to make sure you’re not just putting Alex Rider in a deerstalker. I must, though, give the author very definite credit for the opportunities he finds for widening his own main character. Sherlock is always interested in learning, in finding out how things work, in considering plans by which he might keep track of knowledge. It can sometimes be a little forced or arbitrary, but it does have the merit of giving the reader some insight into the origins, for example, of hot-air balloons.

One item in particular stands out, and surprised me not a little: as a gift for the voyage, Mycroft gives Sherlock a copy of Plato’s Republic. Sherlock works his way through this during the voyage, in between violin lessons and escaping from paid assassins. At one point, he fires a ball-bearing from a sling and causes a man to die. It’s very definitely a moment of self-defence, but the book does at least pause briefly to consider the effect of taking another’s life. Later, he has to decide whether he has the right to prevent the United States army from destroying the Confederate Army. He ponders the clash of moral codes, and wonders whether anyone has the right to enforce a moral code. I don’t say that it’s a very insightful moment, but I do respect the attempt to address more important matters: and in this, Young Sherlock Holmes is definitely a step ahead of Alex Rider.

Tim Golden is a computer programmer living in London. He is also the editor of the Good-to-Read website.