Take out the very superficial puzzlement about identity that one character *almost* has, and this is a very tired, very cliche, very poorly written book about two people falling for one another in the most boring ways possible.
I should have loved this book. Lesbian dealing with alien invasion and mind control issues coupled with thoughts about aging, letting, go, accepting change, and can you be human without struggle? Sign me up!
I actually think that character building is where Mohanraj really shines. Yes, the world-building is interesting and complex (thankfully we are given the exact right bit of information so that we can follow along and care without getting overly bogged down), but it is the characters who will stay with me.