What's the Name of That Book??? discussion

My coworker was telling me about a book she wanted to get, but couldn't remember the name. It takes place in WWII. A (young) couple gets separated when she is taken to a concentration camp(possibly Auschwitz if my coworker remembered right). The man joins the S.S. in order to look for her

Finding Rebecca by Eoin Dempsey. I just added it to my wishlist a couple days ago.

Thank you!