Gloombringer by Sam Burns

For decades, the four families who rule the Summerlands have been locked at an impasse. No one is fighting, but neither has anyone been speaking.

We don’t have time for that anymore.
Mount Slate, the volcano that sits in the middle of the Summerlands, is threatening to erupt, and only the four family heads working together can avert disaster.
As the right-hand man of the Gloombringer, it’s been up to me to convince first my boss, and now the rest to put aside their differences and work together for the good of the world. The problem is that not everyone is all that interested in the good of the world—not unless they get something out of it. Even worse, I now find myself distracted by the Moonstriker’s envoy, Rain. He’s intelligent and handsome and for the first time in my life, I’m struggling to focus on work. But I have to.
It’s up to us to save the world.
If we can.