Well, it could be a story where an EMT encounters a really strange situation with a patient who is somehow 'unseen'. Maybe it's a case of a presence being felt but not actually seen, like some kind of spooky or unexplained phenomenon during an emergency call.
It's not based on a true story. The plot and characters were crafted by the writer for creative purposes rather than being drawn from real-life events.
One way could be to discuss it with others. Sharing your thoughts and listening to theirs might help you uncover aspects of the story that were previously hidden. Another approach is to re-read or re-examine the available information with a fresh perspective.