Sailor is entering her second year at the Explorer Academy, and the Explorer students discover that they will be travelling in a new ship, the Vela. Sailor is devastated when her older sister Keel mysteriously disappears, but Sailor's parents want her to continue with the school year aboard the Vela. She thinks that her sister might be sending her hidden messages with clues about what happened, and Sailor gets involved with a dangerous secret society. Her friends Cruz and Emmett and Lani are always there to get into trouble and out of it at Sailor's side. But what they don't know is that Sailor is hiding a remarkable secret of her own.

I love this spin-off of the Explorer Academy series! It has all the elements that I loved in the original series: adventure, codes and puzzles, world travel, nature conservation, cool technology, and amazing complex characters.

Sailor was already one of my favorite characters, so it is fantastic to get to know her better in this spin-off. She is feeling conflicted about the expectations put on her by the academy and her fellow students. She feels like she has to perform perfectly and be extraordinary all the time. But through her adventures and the encouragement of her friends and teachers, she learns that she just needs to be herself.
Sailor is also struggling with this unique heritage that her grandmother has told her to ignore and suppress. Sailor feels like she is always hiding, but eventually she finds the courage to be true to her heritage and the abilities that come with it.
She is such a complex character with a lot of layers, and a great character arc as she grows and develops her personality in new ways. And on top of that, she has all these crazy adventures trying to find out what happened to her missing sister!

I really love these Explorer Academy teachers! I am a teacher myself, and it's so great to see how they guide and encourage the students. But they also allow the kids to fail sometimes, because you can learn a lot more from failure than from success.

I enjoyed learning the real history of places they visit, and seeing how they protect animals and explore different ecosystems. It was especially interesting to learn about the migration patterns of monarch butterflies, because I have seen the forests in Mexico with millions and millions of butterflies on every surface. It was the most amazing experience of my life, so it was cool to see that included in this book.

I would recommend this series to readers aged 8 to 80 years. I can't wait to read more from this series!

Disclaimer: I received a copy of this book from the publisher in exchange for a free and honest review. All the opinions stated here are my own true thoughts, and are not influenced by anyone.