This book was an odd recipe that combines college-level physics concepts with a mish-mash of religious parables and spiritual symbols. It sort of felt like there were too many balls in the air all the time. The first dozen or so chapters involve the protagonist flitting about between things she wants to do and fires she has to put out and sort of weird excuses to exposition us (I thought the exposition toward the beginning was particularly cringeworthy, but it got better). Part of that is due to one of the things I paradoxically respect: the author spent a LOT of time and energy making it very clear exactly how much things sucked for her protagonist and those in her world, and while I'm glad she didn't skimp on the details of, you know, how living in a post-nuclear-disaster world means living with the inevitability of aggressive cancer and a 20% infant mortality rate, it also just wasn't enjoyable to read (for me) because of the emphasis put on that. I'm giving it three stars because even though I thought some aspects of it were well done and other aspects of it are things I really respect, I also didn't enjoy reading it. The invaders, meanwhile, call the Sharers 'catfish' and don't acknowledge their humanity.This is an odd one for me. If they are, then their pacifist beliefs keep them from harming them.

What Measure Is a Non-Human?: One of the main concerns for the Sharers is determining whether the invaders count as human according to their philosophical system.

Synthetic Plague: What the invaders are afraid will happen, due to the Sharers' use of genetic engineering.

Super Not-Drowning Skills: The Sharers have bacteria that live under their skin and help them store large amounts of oxygen.

Single-Biome Planet: Shora, which is entirely ocean.One-Gender Race: The people of Shora are all female.Actual Pacifist: The entire Sharer population.

Achilles' Heel: Since the Sharer philosophy says that everything is alive, or has been alive at some point, some Sharers go insane when they encounter stone- since it is 'dead,' it violates their entire world view.The native Sharers spend much of the book trying reconcile their pacifism with the need to protect their planet. The ocean planet of Shora is invaded by outsiders from Valedon who wish to develop the planet. A science fiction novel written by Joan Slonczewski.

A Door Into Ocean by Joan Slonczewski