The first volume of Damian Dibben's fantasy series has arrived on a wave of hype with the publicity campaign's key line emblazoned on the back of the dustjacket  "It's time for a new hero." But then I think we all knew that the book trade and movie moguls are desperate to find a successor to a certain bestselling boy wizard who has hung up his broomstick.

So what are this particular contender's credentials? Could he be a troubled but ultimately brave and resourceful adolescent whose parents have gone missing in strange circumstances? Tick. Is he threatened by a grand conspiracy masterminded by an evil overlord? Tick. Is there an elaborate over-arching plot with missing characters who remain unaccounted for at the end of the first volume, thus necessitating a long sequence of books to work everything out? Tick. Have the film rights been sold? Tick (to Working Title).

Perhaps I'm being a little unfair. There is plenty of clear blue water between The History Keepers and Harry Potter. The hero  Jake Djones (with that irritatingly silent "D")  is pictured on the cover as a T-shirted Justin Bieber lookalike with a big sword, and he does seem older than the early Harry. Jake is on the cusp of all that messy emotional stuff  we're only in book one and already he's wrestling with a powerful crush on another character.

The world of the story is also quite different. Jake discovers his parents are agents of a secret ancient order, the eponymous History Keepers. The order's mission is to guard Time and prevent villains from distorting it for their own nefarious ends. Temporal HQ is at Mont-St-Michel in the 1820s, and time travel is achieved by means of an element called "atomium" and special sailing ships. But ability is involved too, a kind of natural temporal talent called "valour" which Jake has in abundance but as an adolescent can't quite control yet.

The plot depends much more on deduction and action than on magic. Once Jake is involved in the search for his parents the novel becomes a time-travelling detective tale, with Jake and friends forced to work out one conundrum after another. There are desperate chases and hair-raising escapes and Errol Flynn-style swordfights, complicated traps like the puzzle pictures of MC Escher, a complete 16th-century Venetian travelogue and more comical or eccentric secondary characters than you could shake a wand at.

So far so good, and I'd like to be able to say that it all rattles along as a good fantasy should. It is well written, with the occasional lapse into cliché (the sea "flat as a pancake", hills "bathed in sun"). But it takes a while to get going and some of the descriptive passages feel too long. The action sequences aren't bad, but even they go on a bit, and Jake is often rather a passive hero.

Last but not least, the plot is far too elaborate. The bad guy's aim is to stop the Renaissance before it begins, therefore destroying humanism and leaving villainy to reign. Now, I don't mind evil overlords over-complicating things for themselves  it's part of the job description. But this leads to some very tricky passages of explanation, and it could all have been a lot more straightforward, as it will almost certainly have to be in the movie. The old formula still rings true: strong character plus simple story is the best recipe for magic.

Tony Bradman's Tom and the Siege is published by Usborne. Read an extract from The History Keepers here.