Mel still hasn't flown since the crash and Loreen is about to confront him when Yellowknife is rocked by a series of eco-terrorist bombings aimed at stopping Ronnie Dearman's controversial uranium mine. Before long, the police have their suspect in custody - the leader of the protest movement: Bobby's sister, Deanna. Bobby tries to prove her innocence but Deanna refuses to talk. To make matters worse, Bobby discovers that Deanna's daughter Hailey is having an affair with the man he suspects is the real bomber. It all comes to a head when Bobby learns there is one more bomb and it's hidden on an Arctic Air plane, piloted by Krista.