When I first got my Nook a few months ago, one of the first ebooks I read using the "Read In-Store" feature was Sarah's Key by Tatiana de Rosnay.  I'd had it on my wish list for ages, but a friend of mine recommended it, reminding me that I wanted to read it.  "It's sad," she said.

"Sad" isn't the half of it.

The book moves continuously back and forth between two different periods.  In Nazi-occupied France, when Sarah and her parents are rounded up with many other Jewish families, Sarah locks her brother in a secret cupboard in their apartment.  She believes that she'll be back later that day or the next day to free him, but when they are taken to a concentration camp, she becomes desperate to escape and save her brother from his hiding place.

In modern-day Paris, Julia Jarmond is assigned the story of the roundup for the 60th anniversary.  During her research, she runs across Sarah's story, and becomes obsessed with finding out what happened -- and tracking down Sarah.  Her search takes her from the site of a former concentration camp to America and Italy, but it also teaches her a lot about herself.

As the story unfolds, some of it comes as no surprise, while other plot twists successfully take the reader off-guard.  Sarah's story inevitably becomes Julia's story too, as she discovers long-buried secrets in her husband's family's and becomes irrevocably involved in her father-in-law's absolution.  It's a story that is both heartbreaking and hopeful, and will leave you thinking about Sarah and Julia long after you're done reading.