While this is still the original Whelan cover art, the background color has been modified to deep blue (instead of pale blue.)

Gate of Ivrel (1976) - Scattered about the galaxy were the time-space gates of a vanished but not forgotten alien race. In their time, long before the rise of the native civilizations, they had terrorized a hundred worlds - not from villiany but from folly, from tampering with the strands that held the universe together. Now the task was to uproot these gates, destroy their potency for mischief, take horror out of the hands of the few who hungered for power by misuse of the gates. When humans found the Gates, they sent a select hundred through to seal them permanently from the far side. Morgaine, with her sword "Changeling" (built with what humans knew of Qhal technology) was the last of those... On Ivrel, she recruits a local, Vanye, into her service. This is Cherryh's first book (she got the "best new author" John W. Campbell award in 1977.)