Black hole of books?

I'm officially on winter break from school. And I'm in Michigan, visiting my family & friends. Of course, I brought a ton of books with me! I read one whole book on my plane rides. :) Yay!

I started reading the Marked series (or is it the Chosen series and Marked is one of the books?) by Cast & Cast. I was really into it too, it was interesting and I was nearly done. And suddenly, the book has disappeared into a black hole because I can't find the damn thing ANYWHERE!

I was reading it on Monday before my best friend came over. It was dark and she was unfamiliar with the road up to my parents' house. So when she called my cell, I put the book down on my bed (I thought), grabbed my phone and fleeces, and ran upstairs to meet her at the end of the driveway. And later the next evening, after our adventures talking all night and in Ann Arbor, I can't find the book. I thought maybe I had brought it upstairs, but it's not there. I thought it had fallen under or behind the bed, it's not. I thought I brought it into one of the other rooms, it's not there. I CAN'T FIND IT AT ALL! Where could it possibly have gone but in a black hole?

I'm upset because it was good and I'm almost done, but also because it's a library book!!! :(

Wish me luck. My last option is asking my best friend if it somehow ended up in her bag.