Curiosity begins with a question.
It is a writer's job to incite questions within the reader, and these questions begin with the inciting incident: what sets the story in motion.
How is this going to turn out?
This is the key question your reader will want answered by the time they set down your book.
But every scene should raise its own questions, as well, and it's this curiosity and concern for your characters that will encourage the reader to turn page after page to discover what will happen next.
These questions can be mystery or suspense-related. They can elicit anxiety, worry, fear, and even dread if the reader knows what awaits the character before the character knows himself. They can evoke anticipation or doubt until it's absolutely certain the two lovers will end up together.
But an intellectual interest in your story is always rooted in curiosity, and curiosity is only as strong as the questions that are generated through the events your characters face.
Be Brilliant!
~Katie~