This is the adventure of two kids, Sigrid and Rolf, who meet a mountain troll on Hjertaas mountain in Sandefjord Norway. In the end they see all the treasure in his mountain lair and find the secret to his true treasure and theirs. The story is rich with folk lore of nissa's, trolls, huldras even Noekks. Hidden in each illustration is an actual photograph taken on Hjertaas mountain in Sandefjord Norway.