"Older women often feel invisible, but sometimes that's their secret weapon. They've spent their lives as the deadliest assassins in a clandestine international organization, but now that they're sixty years old, four women friends can't just retire - it's kill or be killed in this action-packed thriller by New York Times bestselling and Edgar Award-nominated author Deanna Raybourn. Billie, Mary Alice, Helen, and Natalie have worked for the Museum,...