In the fall of 2018, a bomb goes off at a water-bottling plant in the mountains of southwest Virginia, an incident the FBI declares an act of ecoterrorism. Arrested at the scene is Chris Bright, a mountain hermit with a long history of activism. Unaccounted for-and presumed dead-is Mara Wood, an installation artist who in the last two years has lost her son and left her husband.

But Mara's estranged husband David cannot quite believe she is dead, and as he goes about reconstructing the story of what happened, he begins to imagine an alternate narrative-one in which their son doesn't die and his wife doesn't leave him, one in which his wife doesn't carry on a secret relationship with Chris Bright, a man bent on fighting back against the environmental despoliation of his Appalachian home. Lioness is a page-turning, heart-wrenching examination of extremism: What pushes people to act violently, and is that violence ever justified?