On the last day of her junior year, Aitana meets Caspian Miller, main character of her favourite teen novel, who came to meet his favourite book character. From the parallel universe. Shocked and Desperate for answers, Aitana reveals he only has 24 hours to spend with her, before he has to return back to his world. But when a series of unfortunate events makes Caspian lose his only way to return to his reality, Aitana must help him find his way back home. Following trails with uncertainty, Aitana and Caspian set out on a journey of a lifetime. To the parallel universe, of course.