Maybe it's a group of fans who collaborate on writing this fanfiction. They might each bring their own ideas about Hermione and Professor McGonagall, and combine them to create this story where Hermione screams. There are so many possibilities in the world of fanfiction writing.
One possibility could be accounts of survivors. For example, if it's a shock doc about a natural disaster, the true story might include the harrowing experiences of those who lived through it, their screams of terror during the event. Another example could be in a true - crime shock doc, where the screams of victims might be part of the true story as they were being attacked.
Perhaps there was some kind of magical accident or strange phenomenon that involved Professor McGonagall. Hermione, being the curious and sometimes easily startled girl, might scream in shock when witnessing it.
The name of the novel is "Time Travel and Anti-Time Travel."
"Ghost!" Song Ningzhu screamed in horror. What was that monster in the river with half of its face covered in blood? It was a cursed ghost.
It might be a plot in the Greenwood Saga. The female lead was called Kate. She was alone in her room when she suddenly saw a frog on the bed. She was so scared that she shouted. When the male lead heard the cry, he came to the room and asked the servants to drive the frog out.
According to the information provided, I suggest you read the novel "Infinite Thriller System" because the male protagonist, Jiang Wen, was also forced to partner with the female protagonist when faced with supernatural phenomena and gradually developed feelings for her. Therefore, this novel might allow you to find resonance with your crush and improve your relationship. I hope you like this fairy's recommendation. Muah ~😗