Eighteen year old Aria Patel believes in facts. And here's one of them: a predictable, no-drama senior year is the key to living her best, least complicated life. In the autumn, Aria is heading to her dream school to study Physics, her true love. Unlike "real" love, science is something you can count on.

On an almost regular day, Aria gets a strange text from her mom and heads home to investigate, just in time to see a car careening right towards her parents' car. Before she can warn them, she's overcome by a severe headache. The air in front of her seems to shimmer and waver, swallowing her, as she loses consciousness.

She awakens as herself but in a parallel universe - everything is familiar, yet different. At first Aria is confused about this alternative life, believing it's a dream, or a nightmare, but before she can make sense of anything, she's pulled through the shimmering ripple into another universe and another version of herself. Then it happens again. And again...

Can Aria navigate these parallel universes and get home to save her parents? And will she break one of her own ground rules for living in the multiverse, and fall in love?