I don't know the main theme as the 'watcher true story' is not clearly defined. It could be about vigilance, or the power of observation.
As I don't know the details of 'th watcher story', it's hard to say the main theme. It could be about mystery if it involves a watcher who is observing something strange.
The main theme could be about patience as watching a snail implies a slow and patient activity.
The main detail is the letters. A family got letters from 'The Watcher' in their new house.
Without further information, it's impossible to determine. It could be an ordinary person who found themselves in a situation where they became a watcher. Or it could be someone with a specific role, like a journalist or a detective, if the story is related to that kind of context.
I'm not sure as the information given is very limited. It could be about the people involved in the events of 2016.
I don't have the details of 'the true the watcher story' so I can't precisely name the main characters. But let's consider some possibilities. If it's a fantasy - themed story, the watcher could be a magical being and there could be other magical creatures or humans that interact with the watcher. Maybe there's an antagonist who is trying to stop the watcher from seeing the truth. Without more information, it's all just guesswork.
Well, first, the family moved into the house in Westfield. Then they started getting the letters from 'The Watcher' which contained threats and strange details about their family. They were constantly in fear and it affected their daily lives. Eventually, they had a lot of trouble with the house, like trying to sell it but potential buyers were scared off by the story.
The main event was the family receiving the letters from 'The Watcher'.
The main event was the family receiving those creepy letters from 'The Watcher' after moving into their new home.
The main characters are the family who moved into the house and the anonymous 'Watcher'.