A mystery short story can create tension through its characters' emotions. If the detective is frustrated or the victim is terrified, that feeling spreads to the reader. Also, withholding information from the reader until the right moment can build up a lot of tension.
By using the portrait as an enigma. If the portrait has a strange expression or a mark that no one can explain, it creates mystery. Also, if the backstory of the portrait is only partially revealed.
They often use things like an unknown threat. For instance, in a story, there might be a shadowy figure that the main character keeps seeing but doesn't know who it is. This makes the reader wonder what the figure will do.
Well, one way is to introduce unexpected obstacles or complications for the main character. Another is to keep the reader guessing about what's going to happen next. Also, creating conflicts between characters can add a lot of tension.
One way to create tension is to have characters with conflicting goals or interests. This creates internal and external conflicts that keep the reader on edge. Another approach is to use foreshadowing to hint at something bad that might happen, making the reader anticipate and worry.
You can create tension by setting up deadlines or time limits for the characters. Like, they have to complete a task before a certain time or something bad will happen.
One way to create tension is through character conflicts. When characters have opposing goals or motivations, it keeps readers on the edge of their seats wondering how it'll play out. Also, creating uncertainty about the outcome of events can heighten the tension.
Well, when there are dark settings in a story, it's like a veil is drawn over the normal world. The lack of light hides things. Say, in a dark alley in a story. We don't know who or what is there until something reveals itself. This anticipation builds mystery. The characters are also more on edge in such settings, which adds to the overall sense of mystery.
Use description. For example, describe the locked room as having a strange glow seeping from under the door or making the lock look old and rusty with strange symbols on it. This immediately makes the reader wonder what's inside.
Poe creates mystery by introducing strange events and objects. In his stories, there are often inexplicable happenings. For instance, in 'The Cask of Amontillado', the very act of Fortunato being led into the catacombs for a supposed wine tasting that turns into something far more sinister is mysterious. The use of symbols, like the black cat in 'The Black Cat', also adds to the mystery as the reader tries to figure out what they represent.
A snowman can create tension by being an unexpected element. For example, if a snowman suddenly appears in a place it shouldn't be, like in a locked courtyard, it immediately makes the reader wonder how it got there. This mystery surrounding the snowman adds to the overall tension of the story.