One reason could be that she is a hostage. In a thriller story, villains might gag her to prevent her from screaming for help and alerting others. For example, in a bank robbery, if the robbers take a girl hostage, they would gag her to keep her quiet during their escape.
Maybe she is part of a magic act gone wrong. As I mentioned before, a magician could accidentally gag her while trying to perform a trick. Or in a prank scenario among friends, they might play a joke on her by gagging her playfully, but it could turn into an interesting story situation.
Perhaps it's part of a prank that has gone too far. Some irresponsible people might think it's funny to play such a cruel 'joke' on her without realizing the seriousness of their actions. However, this is still a very wrong and illegal behavior.
Sometimes, it could be a case of a mentally ill person. They might kidnap the girl on an impulse and gag her out of fear that she would escape or attract attention. They may not have a well - thought - out motive like ransom or revenge, but their actions are still very dangerous.
Perhaps she has uncovered a big secret in a corporate or political conspiracy. The people behind the conspiracy don't want her to expose them, so they tie and gag her on her tiptoes to keep her silent. They may be planning to move her to a more secluded place later to deal with her more permanently, but she might be rescued by an unexpected hero who stumbles upon the situation.
One reason could be that the robbers are just looking for easy targets. They see the girl as an easy victim, perhaps because she is alone or looks vulnerable. So they tie and gag her to quickly take her belongings without any resistance.
In a mystery story, it could be that she knew some secret that someone didn't want her to tell. So they tied and gagged her near the stove to keep her quiet and perhaps as a form of intimidation.
In a very imaginative story, there could be a magical or supernatural element. A soccer girl might have unknowingly entered a forbidden area on the soccer field that is protected by some magical creatures. These creatures don't understand human ways and see her as a threat, so they tie her up and use a sock to gag her to keep her from making noise that might attract other humans.
One reason could be a prank. Just like in a schoolyard or a neighborhood where kids might play a not - so - nice joke on each other. Another reason could be in a mystery or crime - related scenario. Maybe he saw something he shouldn't have, like a robbery or some illegal activity, and the wrongdoers tied and gagged him to keep him quiet.
In a horror - themed story, it might be related to a serial killer. The killer ties and gags the girl to subdue her before carrying out his evil plans. The muffled screams add to the sense of horror and helplessness, making the situation extremely terrifying for the victim.
Maybe it's a horror - themed story where some kind of supernatural entity has put her in this state as part of a curse or a dark ritual. It could be used to create a sense of dread and danger in the narrative. Another possibility is that it's a story about a miscommunication or false accusation where the girl has been wrongly restrained, and the story then focuses on clearing her name and getting her out of this unjust situation.
One reason could be that the reader has stumbled upon a secret. For example, if the story is set in a world of spies, the reader might have accidentally overheard some top - secret information and the villains want to keep him quiet.