Secret of the Broken King by Eliza Raine

I’m going to try and pull off the heist of a lifetime. And honestly? Stealing a magic ship from the underwater palace of one of the most powerful – and angry – gods in the whole of Olympus is probably the worst of my long list of bad decisions.
Not just because Poseidon is freaking terrifying. But because he has a secret.
And I’m it.
I’m his secret wife, powerless and cast out of my home.
If he catches me, it’s all over.
So why the hell am I risking my ass?
Because my sister is turning to stone, and I’m all she’s got. I’ll risk anything for her, including the devastating ocean god’s mighty wrath.
But when I discover there are more secrets in Poseidon’s palace than I ever imagined, I realize it might not just be my ass I’ve put on the line.
The King of the Sea is broken, and if I don’t get out soon, my heart is at real risk of going the same way.