17-year-olds Lizzie, Ella, and Betsey Best grew up as identical triplets... until they discovered a shocking family secret. They're actually closer than sisters, they're clones. Hiding from a government agency that would expose them, the Best family appears to consist of a single mother with one daughter named Elizabeth. Lizzie, Ella, and Betsey take turns going to school, attending social engagements, and a group mindset has always been a de facto part of life...

Then Lizzie meets Sean Kelly, a guy who seems to see into her very soul. As their relationship develops, Lizzie realizes that she's not a carbon copy of her sisters; she's an individual with unique dreams and desires, and digging deeper into her background, Lizzie begins to dismantle the delicate balance of an unusual family that only science could have created.

(Synopsis fra goodreads)