When twelve-year-old Freya Lindqvist finds a battered notebook hidden inside her great-great-uncle's old writing desk, she uncovers a secret that has waited 150 years to be found: a second parchment, written in the same runic cipher as the one that sent Professor Lidenbrock into the earth. Only this one points somewhere the professor never dared to go.

Armed with a coded map, a compass that doesn't point north, and her fiercely competitive cousin Magnus, Freya sets off for Iceland, climbs into the smoking throat of a dormant volcano, and descends into a hidden world of underground oceans, glowing caverns, prehistoric creatures, and a lost civilization that has been waiting centuries for someone to come home.

Packed with science, cryptography, volcanoes, dinosaurs, sea monsters, family secrets, and edge-of-your-seat exploration, The Sneffels Code is a thrilling adventure novel for readers aged 9–12 who love Jules Verne, mystery, survival stories, and journeys to impossible places. Perfect for fans of classic adventure fiction, geology, ancient mysteries, and anyone who has ever wondered what's really underneath their feet.