The book is published both as paperback and hardcover. It consists of 17 Chapters.
Meet Hilda: explorer, adventurer, avid sketchbook-keeper and friend to almost every creature in the valley! Join our beloved heroine as she encounters her very first troll, negotiates peace with some very persnickety elves, and reunites two lovelorn ancient giants. Fantastic creatures and daring adventures are all just part of another average day for Hilda, but what will she do if she is forced to move to Trolberg city, far away from her beloved valley home?
The story starts with Hilda’s encounter with a troll, that follows her home after she ties a bell to its nose and leaves again when she removes the bell. Although she survives the encounter, her mom Johanna is understandably not happy about Hilda getting so close to a troll rock.
Later that evening, Hilda and Johanna receive another tiny, mysterious letter (the sixth one already that week) in which an unknown sender demands that they leave their house. The letter is followed by an attack from tiny, invisible creatures who call themselves “the hidden people of the Northern Elven Counties. They cause a lot of damage to the house before Hilda is able to drive them out with a broom. She sends them a letter back in hopes of reaching an understanding.
The letter works since Hilda is visited in her room that night by an elf named Alfur. He helps her fill in the proper paperwork so she can see the Elves, and shows here there is an entire elf village right outside her house. He also explains that the new Prime Minister has promised to get rid of the humans living next to their village, hence the letters and the attack. Alfur agrees to arrange a meeting between Hilda and the Mayor. Before Hilda goes back to bed, she spots a giant. When Hilda tells her mom about Alfur and he Giant the following morning, Johanna thinks it was just a dream.
When Hilda meets the mayor, he is both uninterested in helping her, and unable since the while eviction was the Prime Ministers idea. He also refuses to tell Hilda where she can find the Prime Minister. Only after his pet cat Angelina crawls into Hilda’s hair, and Hilda refuses to return her, does the Mayor give in and tells Hilda what she wants to know. The Prime Minister is in the Caves of Kismet. Alfur warns Hilda that the cave is dangerous, and anyone who enters has to pass three tests of courage, skills and exceptional Braininess. Hilda faces the tests head on; first she is attacked by a large group of Elf Soldiers called “The Light Brigade”, but Twig scares them off. Then she has to navigate a very narrow and slippery path into the caves, and finally she must solve a riddle which of two caves, guarded by two Water Spirits, is the one where the Prime Minister lives (with the other supposedly containing a flesh eating troll). She passes all three and meets the Prime Minister. Despite Hilda’s pleas that she and her mum will be more careful not to disturb the Elf community, the Prime Minister can also no longer end the conflict. At this point, only the King can do that. And the Prime Minister refuses to tell Hilda where the king lives.
Disappointed, Hilda returns home, where her mom tells her they will visit Trolberg the next day. That night, the giant comes back. Hilda tries to get his attention, but fails. While visiting Trolberg, Hilda and her mom end up in an argument since Hilda absolutely doesn’t want to move. When night falls and the giant returns for a third time, Hilda uses a Woff to reach him so she and the giant can talk. The giant claims he keeps coming because he was supposed to meet a friend, but he fears she won’t come. He returns Hilda to her home and leaves. The following morning, Hilda visits the Wood Man to learn more about the giant. In a book of his, she reads that the giants name is Jørgen, and that he belongs to race of ancient giants that used to live in the valley before humans forced them to leave.
When Hilda returns home, she finds her mom packing their stuff. She received another letter from the elves, and has made up her mind; they will move to Trolberg tomorrow. Hilda’s only hope is to talk to the Elf King. Alfur can’t tell her his location either since he signed a secrecy form, but gets around this by pointing out the King’s castle on a map; it is on Bobblehat Mountain. On their way to the top, Hilda and Alfur run into an angry weather spirit that nearly burries them in snow, but Hilda is able to amuse him with some elf jokes and he leaves them alone. Hilda then tries to speed up the journey by hitching a ride on a Woff, but it shakes her off near the top.
Hilda is at least close to the castle now, but first she and Alfur have to hide from an avalanche. The cave they hide in turns out to be the ear; the mountain is actually a giant. Hilda wakes up the giant, and realizes she is the friend Jørgen was waiting for. The tremors caused by the giant’s awakening almost destroy the Elf King’s castle, but Hilda is able to save it. She then falls off the mountain/giant herself, but is saved in turn by Jørgen.
Jørgen and his girlfriend are reunited, and the Elf King decides to end the conflict between his people and Hilda now that she saved him. All seems well, until Jørgen accidentally steps on Hilda’s house, completely destroying it. The two giants follow their fellow giants into space, while Hilda and Johanna spend one last night in the wilderness in Hilda’s tent before moving to Trolberg the following day. Alfur decides to come along too.
- Elf King
- Elf mayor
- Elf Prime Minister
- Prime Minister's cavalry (called “The Light Brigade” here).
- Jester elf
The book adapts the first two episodes of the series, but takes some liberties with them:
- Hilda and Johanna’s roles in regards to the Wood Man are reversed, with Hilda being annoyed at the Wood Man entering her house uninvited while Johanna has less trouble with it since he is harmless.
- In the animated series, Johanna does not find out about Hilda running into the troll.
- In the animated series, Alfur doesn’t seem too bothered by Hilda taking Angelina hostage. Here, he calls her out on it and claims she’s a bully.
- In the animated series, the cave where the Prime Minister lives is not given a name, and Hilda does not have to go through the tests involving the slippery path and the riddle to get in.
- In the book, Alfur takes the Nittens back to Angelina after Hilda and Johanna find them in Hilda’s hair. In the animated series, she brings them with her to Trolberg.
- In the animated series, Hilda briefly meets Frida and David while visiting Trolberg. They do not appear in this book.
- In the animated series, Hilda does not encounter a weather spirit on her way to the Elf King.
- The animated series makes no mention of there being a rule that forbids Elves from speaking about the location of the King’s castle.