Those We Lose

There's only one person in the ruined world Agatha loves more than anyone or anything: Her sister, Astrid.
The pre-war vault dwellers thrust into the Capital Wasteland and settling into Rivet City hold on to each other for dear life, the last connection to home, family and peace.
So when Astrid goes missing, Agatha will do anything--absolutely anything--to get her sister back. She will scour the dangers of the wasteland on her own if she has to, even if it means betraying her best friend, Danse, and becoming an enemy of the powerful force she swore allegiance to: the Brotherhood of Steel.