Captive by Nhys Glover

Abducted from Earth, held prisoner in a surreal cliff-top mansion overlooking the sea with a huge tortured alien, and expected to breed to create a hybrid warrior race capable of taking over the galaxy… Well, let’s just say a shy computer geek like me should be overwhelmed by such a future. But I’m not. And together with the males imprisoned with me, I’ll fight to escape my fate.
But escaping captivity proves far easier to accomplish than avoiding my destiny as the mate of the four alien brothers who claim me as their own. Even if it means rejecting the kind of love I’ve only ever dreamed of, I’ll do anything to save them from themselves and the terrible fate they seem so willing to embrace.