Often, it involves exploring the unique bond and adventures between the human Tardis and the Doctor. There's a focus on how this unconventional setup changes their dynamic and the challenges they face together.
In the fanfiction, the 11th doctor, with his eccentric and energetic personality, could initially be a bit confused by the 13th doctor's more modern approach. But then they could start to combine their wits. For example, the 11th doctor's knowledge of ancient alien races could be paired with the 13th doctor's understanding of current galactic politics. They could work together to save a planet that is on the brink of destruction due to a complex web of time - related issues. The encounter could also lead to some humorous moments, like when they argue about who has the better sonic screwdriver or who has had the more exciting adventures.
One possible plot twist could be that they find out they are both parts of a larger plan by an unknown enemy. Maybe an ancient force has been manipulating their timelines to bring them together for some sinister purpose.
One possible plotline is that they meet in a time - locked situation. They have to work together to break the time lock. Another could be that they meet because of a shared enemy that has somehow found a way to target both of their timelines. They would then have to put aside their differences and use their individual strengths to defeat the enemy.
In fanfiction, when the 11th Doctor meets the 12th Doctor, there could be a clash of personalities at first. The 11th is so full of child - like wonder and the 12th is a bit more reserved. But then they might find common ground in their love for the TARDIS and for saving the universe. They could end up learning from each other. For example, the 11th Doctor might teach the 12th how to be more carefree sometimes, while the 12th Doctor could show the 11th how to be more strategic in dangerous situations.
Well, it varies in different fanfics. The 11th Doctor could be hurt by powerful villains, or maybe in trying to save someone. It could also be from internal conflicts or emotional stress.
It could be due to various imaginative plot devices created by the fanfiction author. Maybe in a battle with a powerful villain or during a risky adventure.