'Sleeper', the debut by J. D. Fennell, is marketed as a young adult thriller. Yes, it is that and much more. The book is also a masterful melange of fantasy and war-time chaos. The protagonist Will Starling is a sixteen year old and he must keep a mysterious notebook out of the hands of VIPER, a murderous bunch of villains. After being shot and fallen into the icy water near Dover, he is rescued only to discover his memory is gone. You might think that this is some sort of homage to Jason Bourne, but 'Sleeper' is different. Very different.
Slowly but surely the memory of Starling returns and he understands that he's no ordinary lad. He's been trained to kill and to maim. As could be expected the story takes place at the backdrop of air raids on London, which adds another layer of fear and chaos to 'Sleeper'.
Just a few pages into the tale, I was certain that this was no ordinary thriller. This was something new. If I were a native English speaker, I would be able to say that it is a ripping yarn told at breakneck speed. What can it be compared to, I wondered aloud. In the end I decided 'Sleeper' might well be a start to a wonderful series that emulates the movies about 'Indiana Jones' with elements of Young Bond (by Steve Cole) and Alex Rider (by Anthony Horowitz) thrown in for good measure.
This is a thriller I would certainly highly recommend to young adults, but more adult readers might find 'Sleeper' also very entertaining. If I were pressed to mention a minor negative, I might mention that I missed a bit of British tongue-in-cheek humour to lighten the narrative a bit at opportune moments. But I would only mention that after a fair bit of torture.