Book One introduced the planet of Meniscus, which travels around two suns and has two moons. The atmosphere is breathable, but water does not behave like water on earth; it flows upward.
Meniscus has a dystopian society and is populated by a variety of unique sentients (intelligent beings), animals and plants. Some are benign and others deadly.
Dock-winders, the dominant sentients, are oppressive with no evident morals or ethics. The humans on Meniscus were abducted from earth to be slaves, but humans do not accept captivity passively. There lies the underlying plot of the series: survival and the quest for freedom.

Alexandra Tims is also an artist. Each book begins with a map of the relevant segment of the planet, and her sketches of the characters and significant scenes add depth and connection.
Meniscus is an unusual planet, so Tims ends each book with descriptions of the cast of characters, a glossary of the plant and animal life and a guide to Gel-speak.

Drag-on is a sentient, telepathic Hooplore. They resemble nests of cooked spaghetti and roll and bounce like tumbleweed. They are rather aloof from other Meniscus aliens and helpful to Humans.

Book Ten, Meniscus: Rosetta Stone, introduces new characters, Abra and Trath. They escalate suspense and emotion and create hints for the future.

Abra finds a manuscript, a rosetta stone for those who resist, but there are dangers and obstacles to be overcome to bring it to the human settlement. I feel the winds of change and hope, but the cost is high.