it runs in the family trolls

I don't really know. It could be inspired by real-life incidents or completely made up. Maybe check the author's notes or reviews to get a better idea.

Yes, it is. There are real - life cases where certain behaviors or events related to abduction seem to be more prevalent within a family. This could be due to various factors like a family's history of criminal behavior being passed down through generations, or a dysfunctional family environment that leads to such extreme actions being more likely to occur within the family unit.

There may not be any official rules. But perhaps they have unspoken etiquettes like not being too mean if they don't like it.

They might get really excited and start comparing it to their own experiences in the Trolls world. Maybe they'll laugh at the funny parts or feel inspired by the creative interpretations in the fanfiction.

Since I don't know the exact story, I can't say for sure. But it might have family members like parents, children, and grandparents as main characters.

Another theme could be unity. Christmas is often a time for family to come together, and if something runs in the family in the context of a Christmas story, it could show how the family unites around that shared element, whether it's a story, a custom or a value.

Well, in fantasy fiction, cave trolls differ from other trolls in several ways. For one, their physical features might be more suited to cave living. They could have a thicker hide to protect against cave - related hazards. In terms of behavior, cave trolls are usually more territorial about their caves. While other trolls might be more nomadic or have a wider range of movement. Also, the diet of a cave troll is likely to be more limited to what is available in or near the cave, such as bats or underground fungi, as opposed to other trolls that might have a more diverse diet depending on their habitat.

Perhaps it's a story of a family where abduction has become a sort of 'tradition' in a very dark sense. It might start with one family member committing an abduction and then others being influenced or having some sort of family - bound reason to follow suit. It could explore the psychological and social factors within the family that lead to such a disturbing pattern.

Another theme could be shared family characteristics. For instance, if all family members are really into nature exploration during summer, it shows a common trait that 'runs in the family' in the context of the summer story. This could also be about a shared sense of adventure or love for a certain summer pastime. It could also be related to family values that are especially highlighted during the summer months, like spending time together and making memories.

One such novel could be 'The Boarding House Legacy'. It tells the story of a family running a boarding house in a small town before 2007, dealing with various challenges and heartwarming moments.