One possible plot twist could be that they immediately recognize each other as allies against a common enemy. They might join forces right away and start planning their strategies. This would be different from the show where they had some initial hesitations.
Their relationship could develop more quickly into a romantic one. Without the political intrigues and power plays that delayed it in the show, they might fall in love faster. They would be able to support each other more openly from the start.
The main characters are Jon and Daenerys. Jon, who has a complex past including being a bastard in the North but also having a key role in the fight against the White Walkers. Daenerys, who has journeyed across the sea, freed slaves, and amassed an army. In the fanfiction of their meeting, they are the central focus, their actions and interactions driving the story forward.
In a 'Jon Snow and Daenerys meet' fanfiction, they might initially be suspicious of each other. Jon, being the honorable man he is, could be cautious about Daenerys' claim to the throne. Daenerys, on the other hand, might see Jon as a potential threat or an ally she can use. They could start by exchanging stories of their respective journeys, with Jon talking about the Night King and the threat from the North, and Daenerys sharing her experiences in Essos. Eventually, they might form an alliance to fight their common enemies, and who knows, perhaps there could be a romantic connection between them as well.
Another scenario could be a more tense meeting. Jon arrives with a bit of suspicion towards Daenerys, as he has heard tales of her conquering ways. Daenerys, on the other hand, is cautious of Jon as she doesn't fully trust the North. But as they talk, they gradually realize that they need each other to face the greater threats that loom over Westeros, like the White Walkers.
One possible plot could be that Jon Snow, on his journey north of the Wall, somehow gets lost or is magically transported to where Daenerys is. They immediately recognize each other's importance. Jon, being the honorable man he is, offers his help to Daenerys in her quest for the Iron Throne. Daenerys, in turn, is intrigued by Jon's tales of the North and the White Walkers. They form an alliance early on, which changes the course of the entire Game of Thrones story, with their combined forces being a formidable power in Westeros.
The main antagonist could be Littlefinger. He sees the early alliance between Jon and Daenerys as a threat to his own schemes. He might try to manipulate events to turn them against each other. He could spread false rumors about Jon's intentions towards Daenerys' claim to the Iron Throne or vice versa. His sly nature and ability to play the game of thrones from the shadows would make him a formidable foe to their budding relationship and their plans for Westeros.
One interesting plot twist could be that when they meet, they find out they are related much earlier than in the original series. This would completely change the dynamic between them, especially if there were any romantic undertones developing. Another twist could be that Daenerys initially refuses to help Jon against the White Walkers because she believes it's a ploy by the other Westerosi lords to weaken her. Or perhaps Jon discovers a secret about Daenerys' dragons that makes him question her true intentions.
In fanfiction, when they meet, they might immediately sense a connection. They could start as allies, with Jon being in awe of Daenerys' dragons. Their relationship could be a key to uniting the Seven Kingdoms against the White Walkers, with their combined strength and leadership being a powerful force.
There could be. Fanfiction is a vast world where fans can take the story in any direction they like. Since Jon and Daenerys were significant characters in the series, it's not uncommon for fans to write about them. Regarding a story where Daenerys is pregnant, it might be a way for fans to explore their relationship further, perhaps imagining a different future for them. You could also try looking on Wattpad in addition to AO3 for such fanfictions.