This book was written in present tense and first person, which took me a little getting used to, but it was well suited to the story. There are two protagonists and the author does an excellent job of giving them their own voices: if I didn’t check who was narrating any particular chapter, it would be obvious from the writing which character was providing the current point of view.

There are two ways in which the portrayal of science and atheists bothered me. The main characters are supposedly atheist, but they really just substitute Newton for God and rever him in a vague and unsettling way. The main conflict essentially boils down to the idea that farming genetically modified crops is dangerous and it would be better to go back to traditional farming, which is in direct conflict with real life scientific consensus.

The rest of the science was handled well, accepting of course that the book is sci fi and not speculative fiction. And the plot of separation and reconciliation between the siblings was uplifting and positive. I would recommend this book to young readers, especially those who have an interest in trivia or bugs (one of the girls is fond of fun facts), or those who are interested in a story about how two very different siblings can learn to get along better. Adult readers may find the plot too simple and straightforward for their taste.

As a final note, the main characters have a great deal of interesting devices and apps, many of which are realistic (like smartwatches that monitor the kids and give health advice), and I loved the clever names for these.

A climate change science fiction book about a set of identical twin girls, in which one girl disappears into a sinkhole. The other twin searches for her missing twin, because you can't be twins with only one girl.
My girls really liked this one, the boys, not so much. But it is a charming story. I recommend it for tweens (my boys are preteens).