Otherworldly - Kassien And Calypso's Song, #1

In a distant future, humans are on the run from the Warrior Alphas, who have taken over the planet. Only old, leather-bound books pulled from the rubble tell the story of who once inhabited Earth. Calypso is one of the last survivors. She's different than the rest of her kind, her hair a silvery blue and her eyes like ice due to a gene mutation from a past nuclear fallout. She has always been warned about the large, merciless enemy, and that if they found them, they would be killed or enslaved.
One night, Calypso is attacked by one of their own. To her surprise, one of the alien males - Kassien - saves her and sets forth a chain of events that changes their lives, and the future of their races. Content warning: this book contains graphic sex, violence and scenes of dubious consent, and is not suitable for readers under the age of 18.