Pastworld by Ian Beck is published at the end of September in the US and early October in the UK by Bloomsbury.
I like the sound of this as it sounds a mix of science fiction and mystery (and possibly romance?).
Pastworld. A city within a city. A city for excursions and outings. Pastworld is a theme park with a difference, where travellers can travel back in time for a brush with an authentic Victorian past. But what if the Jack the Ripper figure stopped play-acting and really started killing people? For Caleb, a tourist from the present day, his visit goes terribly wrong when his father is kidnapped and he finds himself accused of murder. Then Caleb meets Eva Rose, a Pastworld inhabitant who has no idea the modern world exists. Both Caleb and Eva have roles to play in the murderer's diabolical plans - roles that reveal disturbing truths about their origins.
Visit the official Pastworld website.