However, because of a topological twist that she does not notice until too late, the sort of "time travel" that she experiences in this young adult novel is unlike any I have seen before. She stays the same age and in the same grade at school, but (contrary to expectations) everyone else ages and moves on. Furthermore, since she is caught in a time loop of repeating freshman years, she sees the students who were her classmates grow up. At one point, she meets Vera who was her best friend in middle school but abandoned her to hang out with the cool kids in freshman year. However, when they meet again, Vera is an adult and working as a child psychologist. Moreover, Vera doesn't remember Nephele. Most of the people who knew her before end up essentially forgetting her as a result of the cognitive dissonance the time travel has caused. The problem is even worse in the case of Nephele's parents who do remember her but have a mental breakdown whenever they are reminded about any of the contradictions she created.

Nephele, who surprised her kindergarten teacher by estimating the area of a circular rug in square meters and was reading calculus books by second grade, is a math prodigy. The book makes it quite clear that it is mathematics which allows her to travel in time, even if it was high school drama which inspired her:

Unsurprisingly, the more specific math, computer science and physics ideas used here to explain time travel don't make much sense. For example, here is where she describes the smartphone app that she is writing to allow time travel:

But, I admit that I did sort of like the way some higher math gets brought into it later in the book when she realizes that she unintentionally caused knots in the fabric of spacetime which are responsible for the problems. This allows for a brief discussion of knot theory and the idea that it might be possible to untie the knots in higher dimensions. Other mathematical concepts that are touched upon include weird numbers, the liar's paradox, and fractals.

The major focus in the book is on her relationships with other people, especially a romance with a cute boy named Jazz Shipreck. The novel is not particularly deep, but judged by my usual standard for YA novels ("would I have liked it when I was that age?"), I think it is quite good and recommend it for any young person who likes reading about smart and quirky characters.