Jean's father is a visionary, and he cajoles and convinces humanity to fund an international space station. But before the station is even finished, strange and tragic accidents start killing the astronauts and delaying the project. Jean's father is the last to die--after that, the station is mothballed.
Years later, Jean's old childhood friend Arthur Cluny manages to get politicians to restart the station. He and his friends head up to space--only to find a mysterious message encased in gold waiting for them. Unsure whether the message is from aliens or some terrestrial conspiracy, Cluny tracks down Jean, hoping she can translate it. Jean was once a promising PhD candidate linguist, but when the army took over her project she fled. After a terrifying time in welfare housing, she escapes into the desert, where she finds old friends willing to help her. Among the Indians learning to live on the desert, she begins to find peace and stability for the first time. But then Cluny arrives, and their isolation is shattered.
Using her linguist skills and the different kind of reality the Indians have learned to see, Jean translates the message. The thought of a coming alien visitation convinces the world to band together. However, Cluny and his friends suspect that the message was really terrestrial, and Jean eventually concedes that she thinks it is as well. Scared to let the rest of humanity in on the secret, knowing that it will undo all their work, the cabal tries to kill Jean, but instead she and Cluny escape into the desert.
Wilhelm crafts a world that is truly terrifying--and terrifyingly familiar. Her future isn't perfectly correct: the computers are gigantic and practically calculators, while the USSR is still a major threat. But other bits, like the widening class divide or the way supposedly objective research is often the result of guesswork and the desires of funders, ring true. And unlike a lot of 70s sf, women are not only main characters, but they have opinions and careers of their own. The Indians mostly avoid racist tropes, as well. I was wary of them teaching Jean their ~mystic ways~, but it's made clear in the text that there's been a lot of mixing with the rest of American culture and immigrants, and that they themselves are learning to live in the desert and see a more natural reality. They're not experts because of something in their blood.
All of this is a bit secondary to the really poweful part of Juniper Time, which is the way Wilhelm crafts the inner workings of her characters. She has an amazing ability to bring people's personalities to life.
(trigger warning: there are numerous off-hand mentions of sexual assault, a 2 page gang-rape scene, and detailed emotional aftermath of an assault)