In Acorna's Triumph, Acorna faces her most difficult challenge ever. She has defeated slavers, a deadly international conspiracy, and the vicious alien Khleevi, only to endure the loss of her beloved Aari, distant in both time and space. Now, finally, Aari has returned, and together they can finish rebuilding their home world. But Aari is oddly changed, to the point where he barely remembers Acorna - much less their love - and his actions grow more and more sinister... As Acorna tries to stop a vicious criminal from destroying innocents, a new complication arises. Sensing the Linyaari weakness, the deadly Khleevi return, determined to take back the planet-for good. In this dark time, it will take all of the unicorn girl's courage and determination to rescue Aari and stop the alien menace once and for all.