Necessity: Climate Justice & the Thin Green Line is set along the rivers of Oregon and the Columbia Gorge. We meet Lauren Regan, a criminal defense attorney using this same strategy to defend her clients, including social worker and Umatilla tribal elder, Cathy Sampson-Kruse, arrested for blocking a megaload carrying toxic materials. Attorney Direlle Calica takes us through intertribal alliances that are at the heart of a regional fight over oil trains and terminals. We hear some of the dilemmas that arise around the use of the necessity defense and see the jury trial of activists using this defense in Oregon. The events unfold around an oil train explosion that came near to devastating Mosier, a small town along the Columbia River. This story of climate resistance along the rivers of Oregon brings into view a historical landscape of tribes resisting oil trains and trucks carrying these highly inflammable products through treaty lands.