How to built up a detective story on the falloing line: My sleep was brocken by the shrill ring of telephone. It was my aunt,saunding very agitated and scared.It took me a couple of minutes to calm her down & get her to tell me the reason for her call.It appeared she had seen a man pushing a woman down from the balcony of a 10th floor flat across the street and was nervous because the man has also seen her watching him commit the crime.Before i could say sth to soothe her frayed nerves, I heard her loud scream on the phone and the line went dead. It took me exactly 15 minutes to reach my Aunt's place but what I saw there was shocking beyond words--------------
"Her apartment was trashed, like a tornado had ripped through. The phone was ripped out from the wall, which explained why the line had gone dead. I was just about to pull out my cellular phone, when I saw the message on the post it note where the phone had been: 'Call the cops, and she is dead.'"
"My mind raced. I had to find out who had killed my Aunt's neighbor and kidnapped my Aunt. I also had to find a way to alert the authorities without tipping off the kidnapper."
That's just an example of how I could set up a mystery, with plenty of suspense. You could also set it up as a tragedy: the police were already there and found your Aunt's body, and signs of a struggle. Or you could arrive to find her dead. Or you arrive in time to foil a would be murderer, but a mask prevents identification. The possibilities are endless, the only caveat is that you don't reveal who had motive means and opportunity until the very end. And make sure you have at least 1 red herring who has two of the three elements (e.g. means and opportunity, but little if any motive).