It almost feels like you're stretching your three-act structure between three books. Is this book stand-alone? Is there an ending-for-now? Because that first beginning of that book ought to have some sort of, no, aliens don't exist, or no, I'm not the right person for this job, or even no, i don't wanna go because this sounds hard and all i want to do is watch tv on the beach.

I would say dig deeper. Make it about this character, this book, and forget 2 and 3 for the moment. They'll follow with the major arc that isn't -quite- concluded. But there needs to be an arc for just book 1 and the characters in it.