Whipping Star

In Whipping Star, Jorj X. McKie, a "Saboteur Extraordinary," is a born troublemaker who has naturally become one of BuSab's best agents. As the novel opens, it is revealed that Calebans, who are beings visible to other sentient species as stars, have been disappearing one by one. Each disappearance is accompanied by millions of sentient deaths and instances of incurable insanity.

Ninety years prior to the setting of Whipping Star, the Calebans appeared and offered jump-doors to the collective species, allowing sentients to travel instantly to any point in the universe. Gratefully accepting, the sentiency didn't question the consequences. Now Mliss Abnethe, a psychotic human female with immense power and wealth, has bound a Caleban in a contract that allows the Caleban to be whipped to death; when the Caleban dies, everyone who has ever used a jump-door (which is almost every adult in the sentient world and many of the young) will die as well.