Return to the Underworld by Skyler Andra

A challenge has emerged for rulership of the Underworld.

Trouble brews between Hades and Autumn. All she wants is to be his equal and rule together. But Hades has gotta be the man, protector and provider, and is pushing her away. When Hades does the unthinkable, the writing might be on the wall for the king and queen of the Underworld.
Zeus broke an ancient oath to never harm another deity by threatening Autumn’s life. War is declared on the Underworld, and Hades must protect the realm and the souls from the threat that wishes to rule them. The gloves are off, and Hades isn’t taking any chances when it comes to his family’s survival. He lost them once and won’t ever again. Sometimes the old Lord of the Dead must do what an Underworld God’s got to do…if only Autumn can forgive him.