Well, I think family could be a theme. In many short story collections, there are often tales that revolve around family relationships. Also, nature could be a theme considering the mention of a pool which is a part of nature. The stories might explore how characters interact with nature.
Perhaps there's a family member, like a grandparent, who tells stories about the secret pool. And then there could be a child who is curious and sets out to uncover the truth about the pool. There might also be a local who warns the characters about the pool for some reason.
Fantasy is likely a main theme too. Since there's a secret door, it might lead to magical or extraordinary places. The other stories probably also have elements of the fantastical, like strange creatures or unusual powers, which all contribute to a fantasy - themed collection of stories.
One main theme could be the exploration of the self. In 'The Secret Sharer', the protagonist's encounter with his double makes him question his own identity and moral boundaries. Another theme might be isolation. The characters often seem to be alone in their experiences, whether on a ship at sea or in other settings.
One main theme could be the complexity of human relationships. In Zweig's stories, he often delves into the intricacies between characters, like the unspoken desires and hidden emotions. Another theme might be the exploration of the human psyche. His characters' inner thoughts and motives are often laid bare, showing how people can be driven by different forces within them.
One of the main themes could be mystery. Since it's called 'The Secret Stories', there's likely an element of the unknown that runs throughout. Another theme might be discovery, as secrets are often uncovered in stories.
The main themes could include the exploration of the unknown. Given the title, it's obvious that the characters are delving into something not commonly known. Another theme might be transformation. As they experience the other side of the secret, they may change in some way. And loyalty could be a theme as well. Characters might need to be loyal to each other in order to survive or understand the secret world.
I'm not sure specifically as I haven't read it. But it might include various adventures or mysteries related to Salty, perhaps some tales about friendship and discovery.
The theme of friendship also stands out. Mary, Dickon and Colin form a strong bond in the secret garden. Their friendship helps them to face their individual problems and grow. Additionally, the idea of secrecy and discovery is there. The discovery of the secret garden is like finding a hidden world full of possibilities.
A third theme could be change. The results of a secret check can often lead to changes. For instance, if a secret check of a school's curriculum reveals that it's not up - to - date, then changes will be made to improve the education quality. So, discovery, suspense and change are likely main themes in 'the secret check stories'.
Another theme could be courage. The kids in the Secret Seven are not afraid to face difficult situations. They might encounter some scary people or be in dangerous places while trying to solve a mystery, but they still keep going. They have the courage to stand up against wrongdoings and to find out the truth.