I just loved Unknown! I really like how the story is going, and there is so much going on.

I find Pearl to be really interesting, especially how she's using children to get to Cassiel. Like, how did she not die the first time, and how did she stay hidden for so long? And how will the children's powers play out?

Unknown is just as exciting as Undone, and Caine is really good at keeping things moving. The action just doesn't stop, and it's impossible to get bored reading it. I think my only complaint is that it moves a little too fast- it would be nice to see Caine slow things down just a little.

Cassiel is an interesting character too, and I like seeing her adjustment to living in a human body. I can't wait to see how she deals with it in the rest of the series.

It gets a 5 out of 5. It's been a fun series to read, and I can't wait to see if Cassiel can save humanity or if she has to destroy it.