Tellus, a Finnish environmental group led by Eevi Forsman, use increasingly radical means to "save the earth". They are pursued by Taneli Lokka, an experienced police detective, who tries to save the earth in his own personal way.
A pub discussion among the five members of Tellus ("Earth" in Latin) about the best strategy to save the planet results in the bombing of an Arctic Mining Co. installation. Taneli (Pirkka-Pekka Petelius), recently recovered from a stroke, heads the police investigation but, with no clues, there is little progress. With mounting pressure from the higher-ups he questions Alex (Lauri Tilkanen) and two other members of an environmental group engaging in street protests. Eevi (Minka Kuustonen), the brains behind Tellus, maintains the required discipline and secrecy, but solitude and grieving for her deceased mother leads to a relationship with Alex.
The next Tellus action topples some electric power lines. Taneli's boss, Reijonen (Heikki Rantenen), relays the minister's displeasure at lack of progress just as the first break occurs: CCTV footage of Janne (Henrik Hammarberg) phoning in responsibility for the latest attack. Meanwhile, Alex's group is growing impatient with his moderate approach. Eevi and Alex have their first date (a bike ride through Helsinki's tunnels), and Taneli becomes increasingly sensitive to the environment, noticing local wildlife (birds) and complaining about his family's waste of food.
The next Tellus attack(on the airport) is aborted when Taneli guesses the target. He begins cross-checking names which leads him to the high school attended by Eevi and others of Tellus. He tells her that Tellus can continue if nobody is killed and she becomes an informer. Taneli reduces his carbon footprint by selling his car and becoming a vegetarian. Daughter Noora(Saga Sarkola), soon to get her driver's license, is upset and son Oskari(Otso Aunola) doubts his individual contribution would help save the planet. In the meantime, Eevi and Alex move closer together.
Alex and his eco-group have a falling out over his moderate approach, the ups and downs of his relationship with Eevi continue, and he meets up with his estranged wife, Sara (Marjut Maristo). Family tension increases as Taneli continues his green campaign whilst Eevi begins to see him as someone she can confide in. After the mock killing of a pro-nuclear minister, Rike (Johannes Holopainen) expounds on Finnish society at the gravesite of Sanna (Anu Sinisalo), Eevi's mother. Meanwhile, Janne continues his anxiety-produced downward spiral with disastrous consequences.
Taneli dies in hospital after being hit by a pick-up truck driven by Janne, who goes home and commits suicide as planned. Eevi tries to move closer to Alex but he wavers because she won't open herself up, and Sara tries to win him back. Adding to his troubles, the tunnel project at work ends, and he is removed as leader of his eco-group. Maria (Anni Turunen) now leads the investigation but has doubts about a "foreign" element, suspecting Eevi of being involved. Eevi quits Tellus ("I'm in love") and moves in with Alex whom she sees as someone with a similar mission.
Rike takes Tellus in a radical direction stating that all life on earth must be saved, even if some humans have to die. After Eevi catches Maria illegally searching her apartment, police pressure ends and she returns to Tellus. She thinks being with Alex can overcome loneliness, but her double life continues after he declares himself a moderate. She gets advice from her father Pekka (Vesa Vierikko) and departed spirits, finally marrying Alex at the house of his father, Fredi (Taneli Makela), while Tellus carries out its next attack in a surprise ending.