"Toxic" is a creative YA sci-fi that primarily takes place on the ship, Cyclo. Cyclo is actually a living organism which is designed to work like a machine. However, Cyclo is dying, and things are changing. Hana was born on Cyclo and has only known the ship. Her mother, Dr. Um, is the ship's geneticist, creating the embryos which will replace crew members as they die of old age, designed to fill a specific role. Dr. Um created Hana in secret and has been working with Cyclo to keep her hidden. Creating a child for anything other than the ship's need is strictly forbidden, and Hana could die if anyone found out.
Hana, like the ship's crew, sleeps within the walls of the ship, where they are given lovely dreams, nutrients, and healing by Cyclo. The book begins when she wakes up after a week- longer than she usually sleeps, and for the first time, Mother is not there to greet her. Fighting with herself, Hana eventually decides to venture out of her small room, which has been her whole life. She soon learns that she is the only person on the ship- everyone else is gone.
Fenn (short for Fennec) is on a small ship, the Selkirk, sent to Cyclo on a mission which they know will end in their death. They are working for the ship's company to collect as much data they can about why Cyclo has failed, and then, as the ship dies, so will they. In exchange for doing so, they have been offered a large sum of money- provided they collect the amount of data they are required to plus that they die (they must die)- to be given to an individual or individuals upon their death. Fenn is doing this mission for his sister, Callandra, who was paralyzed in a mining accident for which Fenn feels responsible. The mood of the crew is somber, as they are all knowingly traveling to their death.
However, when the Selkirk crew arrives, they are surprised that there is a girl on this abandoned ship. As things grow more complex than anticipated and the rules keep changing, they enter a quest for survival to achieve their objectives- and potentially to save their lives (since Hana is not required to follow the rules in their contracts). The high stakes and quick changes give this sci-fi a thriller feel which makes it quite the page-turner!
I really enjoyed this book and found it impossible to put down- the sci-fi elements seemed well-researched and were well-explained despite being complex. The mysteries of what is going on/what happened to the ship and what will happen to the Selkirk crew/Hana really kept the plot moving quickly. In terms of the romance, it was very fast, seemingly insta-love, and it felt very take-it-or-leave-it in that I wasn't invested one way or the other and it felt more like filler. I kept that feeling all the way to the end, and it was really the sci-fi and thriller elements that made this book a fantastic read for me, not the romance.
There are also some interesting messages about genetics/heritage, and how we are not destined to do or be anything. This holds true of both Hana and the ship, Cyclo, who were designed with specific characteristics. Hana also has some elements of impostor syndrome given her Korean/Earth heritage but being born on the ship and from a designed embryo, as if she is somehow lesser for it (she corrects being labeled Homo sapiens to Homo sapiens novum, etc.). She considers and grows as an individual, with her heritage, during the book. Although these are minor plot points, they were interesting to include and added some dimensions to Hana's character as well as interesting thoughts to ponder (with correlates to now).
Overall, I found this to be a fast-paced and intriguing YA sci-fi that I really enjoyed. I highly recommend for fans of sci-fi and thrillers! Please note that I received an ARC from the publisher through netgalley. All opinions are my own.