In some short stories, the intruder's motive could be related to a secret. Perhaps the house holds a secret that the intruder is desperate to uncover. It could be a hidden document, a family secret, or something that the intruder believes is of great value, not necessarily in a monetary sense. For instance, if there are rumors that the house contains a map to a hidden treasure from long ago, an intruder might be motivated to find it.
In 'the intruder short story', it usually involves a person or entity that intrudes into a particular setting. It could be a home, a community, or a specific group. The story might revolve around how the people in that setting react to this intruder. They could be scared, angry, or curious. And the intruder's actions and intentions are gradually revealed as the story progresses.
One possible motive is pure infatuation. The secret admirer might be attracted to the person's appearance or charm and is too shy to express it directly. For example, in a school setting, a student might admire a classmate's beauty from afar.
Once upon a time, there was an old house on the outskirts of the town. One night, an intruder crept up to it. He was a sneaky fellow, looking for some easy loot. He jimmied open a window and slipped inside. But little did he know, a dog was sleeping in the kitchen. The dog woke up and started barking furiously. The intruder, in a panic, tried to run back out the window but got stuck halfway. The owners of the house woke up, called the police, and the intruder was caught red - handed.
There could be various motives. It could be financial problems, where the husband's actions were causing severe financial distress for the family. Another reason could be that the husband was involved in illegal activities that put the wife and their lives at risk. Or maybe there was a long history of emotional neglect and the wife just snapped.
It could be revenge. Maybe someone had a grudge against her and decided to take extreme action.
I'm not sure as the specific 'the intruder short story' isn't described in detail. But usually, there would be the intruder as a main character, and perhaps the person or people whose space is being intruded upon.
One possible motive could be revenge. Maybe the blackmailer felt that the gym teacher had been too strict with them in the past and this was their way of getting back. For example, if the gym teacher had made a student run extra laps for being late, the student might seek revenge through blackmail.
The motive could also be related to envy. He sees all the love and affection around him on Valentine's Day and feels left out. So, he decides to kill those who are in love as a way of expressing his jealousy. He might have grown up without experiencing love, and seeing it on this day drives him to madness. He wants to disrupt the love - filled atmosphere of Valentine's Day.
Maybe she was abused by him and couldn't take it anymore. Or he was cheating and she snapped.
Perhaps the old man in the painting was once wronged in life and his spirit is full of vengeance. When the person who gets killed comes into contact with the painting, the old man's spirit senses an opportunity for revenge, thinking the person might be related to those who wronged him in the past.