Early in her career, Lt. Uhura met a young diplomat from the world of Eeiauo. The two women bonded over music, singing, and the songs of their respective peoples and cultures. The graceful, catlike Sunfall of Ennian even shares songs with Uhura, and the Old Tongue they are sung in, that are not to be shared except with other bards.
Years later, Uhura is now the communications officer on the USS Enterprise, which is on a mission of mercy to Eeiauo, where a terrible plague has broken out. The infected individuals become weak, their fur (or hair, as they make the unhappy discovery that it also affects humans), become stiff and achy, they fall into comas, and die. One of those dying is Uhura’s old friend, Sunfall.
McCoy and others are on the surface working directly with Eeiauoan medical personnel. Chapel is among the humans who have fallen ill.
Spock works out that the Eeiauoans can’t be native to their current world. Uhura has reached the same conclusion from reexamining the songs Sunfall taught her. Together they set to work figuring out where their homeworld is. The Eeiauoans can’t, or rather won’t, help them, because they left their homeworld for what they consider deeply shameful reasons. They don’t even want it being said that there was a homeworld.
McCoy and others on the planet look for a successful treatment or cure. Kirk and the Enterprise, with Spock and Uhura still working on the information they have, to locate the homeworld, head off to find it.
We get alternating sections following McCoy and his colleagues, and, when they find the planet, Kirk, Uhura, Spock, Chekov, the interim Medical Director Evan Wilson, and Sulu beam down to the planet to make contact. What follows is a wonderful tale of worldbuilding, a very interesting alien culture, and the unraveling of a very knotty problem.
The natives on the Eeiauoans‘ homeworld, the Savaoans, are also deeply ashamed of the events that led to the exile of the Eeiauoans. They are not going to talk, even to save lives, until the landing party figures out the reason they won’t talk. It’s complex, fascinating, and frustrating.
The ending is quite satisfying, and then there’s a sort of epilogue, which you may like or loathe.
(Pocket Books/Star Trek, 2000)