In this copy of your form, I've done the following:
- Changed your StoryNo. query to not run on form load
- Added a rule to the StoryNo field to set the query field in the data connection and run the query
- Added sections to your default view to show/hide based on whether rows are returned
The net effect should be that if the story no field is set by the query string parameter, which you have assured me it is, the form will query the library to see if any forms exist for that story number, which you have told me is unique. Hopefully this will be enough to clarify for you.