I read the novel after seeing the movie adaptation, so I had in mind for the actors embody different characters despite differences in some descriptions, including Leslie. This first volume of the trilogy offers an interesting discovery of the world created by the author and his characters. We have a history of travel in time, love (family, friends or more intimate) and adolescents. Due to the fantastic choices, time travel, there are many characters and descriptions to help readers also travel in time. It's pretty well integrated without being too heavy. It is certainly not too graphic when Gwen is in the past, especially in contrast to the immersion in the current London but we believe in it enough to. The characters are simple enough to be suitable for a young audience, while evolving and having still relatively spontaneous reactions. While Gwen is a character who does not take too much advantage and stands back, she is nonetheless sufficiently malignant to keep the story from beginning to end. It was she who unlocks things by its simplicity and freshness. They ask many questions about Paul and Lucy, why do they do that? The mother of Gwen, the lodge and especially the O how mysterious character of the Count of Saint Germain. It's friendly and the secondary cast of characters is rich and varied enough to be entertaining and make a great addition to the plot.
Compared to the film there are quite significant differences. To start the "power" Gwen does not appear to him once, but has already attracted him little trouble, and this allows him to get to know an important secondary character, a bit like a Jenx in the books Kim Harrison or Levet in the series of Alexandra Ivy. Finally, the book ends on the stage of the confessional while the film embroiders from this moment to give a more complex and dramatic tone to the whole. Having directly chained to Volume 2, this does not bother me.
In short, it is a novel that I recommend. Simple, no-brainer, but that does not take its audience for neuneus provided.