An explosion on the Liberty Oil pipeline in Backstrom's childhood home of Cooch County leads his estranged father, Sheriff Blue Backstrom, to Portland. Father and son, along with the Special Crimes Unit, race to find the suspected eco-terrorist, before he/she strikes again. Meanwhile, Backstrom must confront old demons when dealing with his revered father, and romances are stirred when ex-fiancée Amy pays Backstrom a late-night visit.

Key witness in a drug investigation is found dead after escaping from his court-mandated rehab program, and Backstrom must figure out how he escaped and who killed him. However, when the S.C.U. learns that the victim is member of a band and all his bandmates dislike him, they start to believe that the killer may be someone closer than they expected. Meanwhile, Backstrom has reason to believe that Valentine may be more than just his tenant.