As season 3 begins, the Coalition Against Everything Strange (CAES) wins the local election, making life perilous for ninjas, witches, and the unliving. Lars and his mum hide, while Anna trains covertly with the school gym team as cover to reunite with friends and find Lars. Tess conceals her inner witch amid CAES takeovers at school, and Robert works to unite the gang against CAES plans.

Defying parents, the kids regroup, but unity frays: Anna questions her romance with Lars, who must prove his devotion without crumbling. CAES mandates "F" badges (for "fremmed" or stranger) on stranger kids' clothes, endangering half-troll siblings Herman and Caroline, whose mother Torill faces an advisor role to populist mayor Bastian Berg. Caroline rebels, embracing her troll side and fleeing to the woods against Torill's ultimatum, seeking her true self and father.

The friends pursue her, encountering Torill in peril; she warns Caroline's monstrous father will doom her. Surreal woods surprises—a gnome therapy group, troll heavy metal band, ghost family—unfold as doubts arise about Torill's tale. Tension peaks at an eerie bunker where truths collide, testing loyalties, identities, and resistance in this fantastical fight for belonging.