1. suspension
2. apprehensiveness
3. joyous
4. adventurous
5. valorous

If you want to write a mystery story, plan the ending first. you want the story to end in such a away that the reader is completely overwhelmed. Think about what mystery you want your character  to solve. Imagine yourself to be the charecter and that you are solving a case. Think about the mystery from different angles. plan and sketch out your characters. you will get ideas as you go deeper into the story. the most important part is the climax. this is what gets the reader's attention