As humanity seeks to reach beyond its birth star, a ship vanishes in the void of space. In the outer system, aliens arrive, bent on...

...well, humanity will not know what their intentions would have been, because it was humans who started the war when faced with the alien for the first time, when they saw what it was.

Thus began the Contact War.

Now a highly-skilled alien diplomat must learn what these people are and why they attacked. And on Mars, an autistic woman, a brilliant linguist who is an alien in her own society reaches out to try and understand.

Together, they must fight to end the war. The future of humanity hangs in their balance and the peace depends on their unlikely friendship.