You can have the greatest story concept in the world, but unless you have conflict you won’t have dramatic tension.
Basically, your line of conflict is the obstacle course you put your main character through so she wins her goal or mission and regains control of her life. That’s from Spielberg. Remember his definition of story? Someone loses control of his life and then regains it.
Conflict, obstacles, loss of control. These engender dramatic questions that create dramatic tension. The story problem, the outside conflict, tells your reader what to worry about. Soon enough he will discover the protagonist’s inner conflict, his ghosts and hidden demons.
Good storytellers learn how to think about their story. Stories evolve, in our minds or on the page. I don’t believe this process can be hurried. I like to take my time, noodling my story through after inventing intricate, conflicted characters who embark on an adventure.