The Alpha CEO's Fake Beta

Told he was a Beta for fourteen years, Eliot discovers he is an S-class Omega when Trueblood Alpha Arthur Pendelton's rut marks him, leaving him pregnant. Taken in as Arthur's assistant, Eliot learns Arthur's father hid him as a child from a rival clan that killed his parents. They crush the rival's blackmail and capital war, beat an overseas custody suit, marry, and rule Pendelton together.