My name is Cassidy Daniels, and I am viable. That's what they call it now that so many women have died. One day, everything was normal, the next, chaos. It hit us in two waves, a few weeks apart. In the end, 75% of the worlds' population of females was gone, and no one knew why. Everyone knows loss now. Everyone knows pain. People looked to the leaders of our country for answers, for help. Their solution was to open facilities of protection, where those of us who survived could go for safety. If only that were the truth. We live in a new world now. Nothing will ever be the same again. I live each day like it will be my last. There are those hunting us, ready to turn us in to the authorities for food and supplies. There are those hunting us for research, to be the first to solve the mystery of this invisible killer. And there are those few who are looking to protect us, to fight back for the good of mankind. Who will find me first? And can I survive it? My name is Cassidy Daniels - and I am viable. This is my story of survival, of loss, of sacrifice and of love.