Nimona is a story of two misfits. The titular character Nimona is a shapeshifting rebel with a tragic history of rejection. Ballister Boldheart is a newly knighted commoner (unheard of in this futuristic-medieval world) framed for killing the queen. Longing for a friend and itching for mayhem, Nimona searches out Boldheart to become his sidekick. She soon realizes Boldheart isn't the villainous "Queen Killer" he's been made out to be. Reluctantly, Boldheart accepts Nimona's (often destructive) help and together they attempt to clear Boldheart's name and bring down the corrupt Institute that views differences as monstrous.