The venber are super cool hammerhead ski alien maybe hybrid cyborg people with laser bazookas, and unrelated

I think I like this book so much because in hindsight it really marks where everything begins to draw down.

This is a true survival scenario, the animorphs are absolutely miserable for a very long part of the book in stark survival mode, Rachel, sacrifices a foot to save Cassie, Marco keeps them on mission, Cassie is coming to practical terms with the limits of her ethics and a letting the rest of the group know them, or rather the rest of the Animorphs are coming to terms with what Cassie came to terms with books ago that ideals cannot always survive The realities of war, especially when you’re a child soldier in that war, there’s a lot of group dynamic and ethical complexity going on here that continues to its fruition by the end of the series.

And they also get to morph polar bears and kick ass at the end of the book.