I'd say Sheriff Harry S. Truman is important. He has been a key figure in maintaining order in Twin Peaks. In the novel, he may be involved in dealing with the strange events and secrets. Also, the Log Lady might be significant. She has her own unique connection to the mysteries of Twin Peaks, and the novel could expand on her character and her insights.
The themes in this novel are likely to be complex. Mystery is a key one, as it draws readers in to figure out the secrets of Twin Peaks. There may also be themes related to identity. The characters in Twin Peaks often have complex identities, and the novel may explore how these are shaped by the town's history and events. Additionally, the theme of good versus evil might be present, with the town's strange happenings blurring the lines between the two.
One of the main themes is the duality of human nature. In the 'Twin Peaks' novel, we see characters with both good and bad sides, like Agent Cooper who has his kind and determined side but also faces the dark forces in the town. Another theme is the mystery of the small - town life. There are so many secrets hidden beneath the seemingly ordinary surface of Twin Peaks.
A 'adult twin peaks visual novel' could be centered around the complex themes that Twin Peaks is known for, such as duality, the battle between good and evil, and the hidden darkness beneath a seemingly normal surface. It may use the visual novel format to tell a story that delves deeper into the lives of the characters, perhaps with multiple branching storylines. But given the 'adult' aspect, it could also include more mature themes like relationships and adult - oriented character development. But again, this is all speculation without proper knowledge of this specific visual novel.
Agent Dale Cooper is really interesting. He's the outsider who comes to Twin Peaks to solve the mystery of Laura Palmer's death. His unique investigative methods and his unwavering sense of justice make him stand out.