Maybe they cried because they sensed some approaching danger in the night. In many Peter Pan fanfictions, fairies are very sensitive to the changes in Neverland. If there were some dark forces or threats emerging, like Captain Hook planning a new evil scheme, their delicate nature would make them cry out of fear or worry.
It could be that Peter Pan did something that disappointed them. For instance, if he made a promise to them, like always protecting their homes, and then he failed to do so. Perhaps he led Hook's men too close to their hiding places by accident. Fairies in fanfiction often have strong emotions and a sense of justice, so they would cry because of such betrayals.
Perhaps it's a story where the fairies cry because they sense some dark force approaching Neverland. They might be worried about the safety of Peter Pan and the Lost Boys. In the fanfiction, Peter could be initially oblivious to this danger but then realizes it when he sees the fairies' distress and decides to fight against this new threat.
It could be about the fairies crying because Peter Pan has forgotten them. Maybe he's been too caught up with Wendy and the Lost Boys and has neglected his relationship with the fairies.
The main characters could be a young girl who has just arrived in Neverland. She could be the cause of the fairies crying, either because she doesn't understand their ways and accidentally offends them, or because she has a special power that scares them. Peter Pan then has to deal with this new situation, trying to protect the girl from the fairies' wrath while also making peace between them.
Wendy could also be the main character. She might have a special connection with the fairies that no one else knows about. So when the fairies cry, she steps in to help, using her own unique understanding of Neverland.
At night, the fairies' cries can have different effects. Their cries might attract unwanted attention, like from the pirates. Since the pirates are more active at night in Neverland, they could hear the fairies' cries and try to capture them for their own purposes, such as using their magic. So the night puts the crying fairies in more danger.
They might cry because of the threat to their home in Neverland. Maybe Captain Hook is up to some new mischief that endangers the fairy glades.
One great fanfiction could be 'The Lost Faries' where the fairies' cries lead Peter Pan on a new adventure to save their kind. It has a really interesting plot that shows a different side of Neverland.
One popular theme is the exploration of eternal youth. Since Peter Pan doesn't grow up, fanfiction often delves into what that really means. Another theme could be the relationship between belief and magic. If the characters believe in fairies, it often leads to magical things happening. Also, the idea of friendship in Neverland is a big theme. Peter's friendships with the Lost Boys and his relationship with Wendy are often explored more deeply in fanfiction.
In a 'Peter Pan kidnapped' fanfiction, it could start with Peter being lured into a trap by a new and mysterious character in Neverland. This character might be jealous of Peter's popularity and freedom. Once kidnapped, Peter is taken to a hidden place. The lost boys are in chaos without their leader. Wendy, who has a special bond with Peter, decides to take charge. She teams up with the fairies and some of the more intelligent animals in Neverland to track down Peter. Along the way, they face many obstacles and learn more about the true nature of the kidnapper and why Peter was targeted.
The plot could center around her unique abilities. Since she's Peter Pan's daughter, she might have some special powers like flying or the ability to communicate with the fairies better than anyone else. The story could be about how she uses these powers to protect Neverland from a new threat that even Peter Pan couldn't handle on his own. She might also struggle with the responsibility that comes with such great power and the expectations of living up to her father's name.