By Larry Niven and Jerry Pournelle
A new object appears in the night sky and it becomes apparent that it is no natural object and that it is headed to our planet. Humans are excited and fearful, especially as the object does not respond to human efforts to communicate.
Upon arriving, the object, a massive interstellar spaceship, attacks the space station, killing some of the astronauts and capturing several others, mostly Russians and one American congressman.
The aliens are large beings, looking somewhat like a baby elephant, except they have two trunks and their feet are clawed. They are herd animals and have strong herd instincts, even to going insane if separated from their herd for too long.
The alien home world is in trouble, and this ship has been sent out to establish a new home. They intend to conquer Earth, enslave humanity and incorporate them into their herd.
Their weaponry is better than anything humans have and they pretty much rule the sky, blasting anything that they deem offensive. They establish a beachhead in Kansas and force people to surrender to them. Once surrender is accepted, the aliens expect you to stay surrendered. They are shocked and very angry when surrendered humans launch attacks guerrilla attacks against occupying forces. The aliens respond harshly, destroying everyone they consider to be connected to the renegades.
Meanwhile, the captives from the space station and a few more taken from Earth are put to work on the spaceship doing menial chores, mainly cleaning ducts and working in the garden. They use this limited freedom to spy on the aliens and plot against them.
Back on Earth, the Americans and Russians pool their remaining resources and launch several nuclear bombs on the alien foothold in Kansas. The surprise attack works and the alien base is destroyed. But in response, the aliens launch a large asteroid against the Earth, which smashes into the Indian Ocean and kills millions and throws Earth's climate into chaos. They promise to send down more asteroids if humans do not stop fighting and surrender. So humans surrender. Or do they? Maybe humanity has one more act of defiance up its sleeve.
This was an OK story. It was very long and had way too many characters to keep track of. Plus I liked the aliens, I thought they were interesting and had a lot to offer. I would have liked a different ending, with the two sides coming together instead of one defeating the other.