The power of nature could be a theme. Harsh weather, difficult terrain, and the unforgiving elements of the pass can turn into a horror scenario. For example, a sudden snowstorm trapping someone with no shelter or a landslide blocking the way out.
One possible theme could be isolation. The Rohtang Pass is a remote place, and being alone or cut off from help in such a location can be very scary.
There are tales of landslides near Rohtang Pass. Imagine driving along the road and suddenly hearing a loud rumble. Rocks and debris start tumbling down the mountainside. Vehicles can get crushed or pushed off the road. Tourists are left in a state of panic, not knowing if they'll be able to escape in time.
I don't actually know the specific 'Rohtang Pass horror story'. It could be about a spooky encounter during a journey through the pass, like seeing strange apparitions in the foggy mountains or experiencing unexplained noises while camping there.
There was a time when a group of tourists went for a short hike near Rohtang Pass. They underestimated the difficulty and didn't carry enough water. As they climbed higher, they got lost. The weather turned bad quickly. They were cold, thirsty and disoriented. One of them slipped and got injured. They were stranded for hours, thinking they might not make it out alive. Eventually, they were found by local shepherds who guided them back to safety.
Another theme could be revenge. Maybe there is a wronged spirit in the 'magpakailanman horror story' that is seeking vengeance on those who did it wrong. For example, a person who was unjustly killed comes back as a ghost to haunt the people responsible for their death. This theme often adds a sense of justice, albeit a spooky and often violent one, to the horror story.
You could write about haunted houses or creepy old cemeteries. They always give that spooky feel.
One possible theme could be the fear of the unknown. Since it's a horror story, Abigail and Sanam might be facing something they can't understand, like a strange supernatural force. Another theme could be isolation. If they are in a situation where they are cut off from help, it adds to the horror. For example, if they are in a desolate place like an old, empty building in the middle of nowhere.
The theme of lost dreams could also be present. Many people come to Los Angeles with big dreams that often don't come true. In a horror context, these unfulfilled hopes could turn into something menacing. Maybe the ghosts of those who failed are out to haunt the new arrivals, or there are supernatural forces that prey on the desperation of those chasing their dreams in LA.
Another theme might be trust. For example, in a relationship, if one partner gives the other a free pass, it shows a certain level of trust (or a lack thereof, depending on how it's presented in the story). Also, it could touch on the theme of jealousy and how it affects the relationship when a free pass is involved.
Another theme might be self - discovery. As students complete their 12th grade, they may start to figure out who they are and what they want to do in life. Also, the theme of friendship could be present, as classmates support each other through the challenges of the 12th grade.
One possible theme could be the fear of the unknown. Since the knock is something mysterious, it represents the unknown danger lurking.