I think 'Artemis Fowl' by Eoin Colfer is also very popular. The young criminal mastermind Artemis Fowl gets involved in various mysteries and dangerous situations in the world of fairies and magic. It has a great mix of mystery, adventure and unique characters.
One of the best is 'Gone Girl' by Gillian Flynn. It has a complex plot full of twists and turns that keeps you guessing until the very end. The characters are well - developed and the story delves deep into the relationship between a husband and wife.
Mystery young adult novels often have relatable teenage protagonists. For example, in 'One of Us Is Lying', the characters are high school students. They usually have a central mystery, like a crime or a secret. The settings can be schools, small towns, or other places familiar to teens. These novels also tend to build suspense. In 'Miss Peregrine's Home for Peculiar Children', the strange photos and the mystery of the peculiars keep the reader on edge.
One characteristic is complex characters. In adult murder mystery novels, the characters often have their own secrets, motives, and backstories that are gradually revealed as the story unfolds. For example, in 'Big Little Lies' by Liane Moriarty, the characters' seemingly perfect lives are hiding a lot of turmoil and secrets related to the murder that occurs.
Another good one is 'Miss Peregrine's Home for Peculiar Children' by Ransom Riggs. The story combines mystery with a touch of the supernatural as the main character discovers the strange secrets of an old orphanage. There are really interesting characters and a unique plot that keeps you hooked.
Good short mystery adult stories often have complex characters. For example, the main character might have a hidden past that becomes relevant to the mystery. They also usually have a strong sense of setting. A story set in a spooky old house can add to the mystery. Another characteristic is the use of clever plot twists. Just when you think you know who the culprit is, there's a sudden turn that changes everything.
Mental and emotional abuse within the plot can also be disturbing. In some young adult mystery novels, characters might be manipulated or gaslighted, which adds an element of unease. It makes the reader question who can be trusted. Also, when the mystery involves the disappearance or harm of a young character, it can be really disturbing as it hits close to home for the young adult readers. For instance, if a character's best friend goes missing and the main character is trying to find out what happened while uncovering all kinds of secrets about their friend that they never knew.
One popular young adult mystery novel is 'The Fault in Our Stars' by John Green. It has elements of mystery within the story of the two main characters. Another is 'A Series of Unfortunate Events' by Lemony Snicket. The Baudelaire orphans face numerous mysteries as they try to uncover the truth about their parents' death. Also, 'The Westing Game' by Ellen Raskin is a great one, with a complex mystery that keeps readers guessing until the end.
Rather than adult mystery sex fiction, in normal mystery fiction, there are themes like suspense, unexpected twists, and the exploration of human nature. These elements keep readers engaged as they try to piece together the mystery along with the characters.