Set a few decades from now, this SF novel is about an Earth that ha seen better days. The climate of mid-21st Century Earth has pretty much fallen apart. The polar ice caps are gone, leading to a big rise in sea levels. This has forced the creation of cities like New Orlando, and a new Washington DC. That is because the old cities are under water. Common animals like cows and horses are extinct; the situation is no better in the oceans. Earth's population has risen to over 20 billion. Very long range space probes have found an Earth-like planet, in the M51 galaxy.
America would prefer to keep the news to itself, but that becomes not possible, so an international expedition sets off for a trip that takes six months each way (intergalactic travel in only six months?!). Led by Captain Nathan Hawke, some small bits of sabotage are discovered. It's nothing obvious like a bomb found in an inaccessible spot, but someone does not want the expedition to succeed.
The planet Eden really does live up to its name. It has a breathable atmosphere, crystal clear water, abundant plant and animal life, and friendly humanoid natives called the Myng'h. They knew the humans were coming, because Ahn-Ben, their god, told them. Each of the humans has a private conversation with Ahn-Ben. He finds the secret spots in their souls that they don't like to talk about. He also knows a lot about humans.
There are those among the humans who think of the Myng'h as little more than animals to be rounded up and confined to some barren part of Eden. The flood of colonists and corporations would spell the end of the Myng'h culture. Ahn-Ben is not interested in doing anything about it. Can the human expedition keep Eden for the Myng'h?