The two most important things about a suspense story is to 1) keep the reader’s interest and 2) keep the reader guessing as to who the ‘bad guys’ are and how they will be caught.
To keep the reader’s interests I try to drop a clue at the end of each chapter, even if only small clues. For example, early in my book Alex, the main character, left the conference room where a meeting was being held. When he returned he noticed that his back pack had been moved from where he left it. The reader starts to notice these clues and from them starts to develop his interpretation of what and who is involved.
I purposely lead the reader down a path and then throw in a twist that could lead the reader in a different direction. Now the reader has two directions to go, which only adds to the mystery. Then another clue which causes the reader to question his own interpretation of what is going on. This technique causes the reader to re-evaluate his theory. Then another twist. Sometimes I have these twists planned ahead of time. But in some cases they just naturally happen through the actions of the characters.
Never give the ending the plot until you are near the end of the story or when you want it revealed. At that time all the clues that you have been spreading throughout the book come together. Keep your audience guessing and looking for more clues as they read. Again, it all goes back to developing good character descriptions and images in the minds of the readers. Let your characters develop the story.
Author, The Mosquito Bites