I really liked this, and you really left me hanging with Billy holding the alien hostage. I think the start is great, and gets straight into the action with a conflict between man and wife, a conflict most of us can or will experience at some stage.
The action went along at such a pace, that I was worried that the story would be over too soon. But I should never have worried. Because the following chapters introduce more characters and even a genocidal alien queen!!! These other perspectives brought in early on, completely open up the story, making sure the reader knows they're in for a grand adventure.
Oh, and you left the perfect hook. What the hell is Billy going to do with his alien hostage?