Cecilie is a lonely, nerdy, 12-year-old girl, interested in archaeology. Her father owns a large department store in Copenhagen, and her equally overworked mother is in charge of the interior. Her 8-year-old sister, Ida, is an Ill Girl, unlikely to survive her heart disease.
During the holiday season, Cecilie learns about the interesting archaeological discoveries found under the department store. She investigates it with a mysterious, amnesiac boy named Hubert, initially only out of her own interest, but she later becomes convinced that "the secret of Absalon" (a Danish archbishop from The High Middle Ages) can help her sister. As Ida becomes more sick, Cecilie grows desperate, but the experienced, cynical archaeologist Petra, whom Cecilie initially admires, turns out to have a selfish interest in the discoveries. Also, Hubert might have something to do with the secret...
- Angel Unaware: Hubert only finds out himself that he's an angel at the very end.
- Broken Pedestal: Petra.
- Edutainment Show: Not marketed as such, but it certainly does teach history.
- The Glorious War of Sisterly Rivalry: Subverted. With their sharp personality differences, and the way that their parents openly favour Ida and want Cecilie to become more outgoing and normal like her, Cecilie and Ida have all the trappings of the trope - except that they actually love and care deeply for each other.
- Ill Girl / Littlest Cancer Patient: Ida.
- Loners Are Freaks: Averted with Cecilie.
- Mysterious Waif: Hubert is a male version. He has amnesia, has no family, lives with two petty thieves, and isn't even human.
- Tomboy and Girly Girl: Cecilie and Ida.