I'm not sure specifically as it could be a very specific fan - made story. It might involve the character Pain from a particular series kidnapping the character Sakura. Maybe it's a story exploring dark themes, power dynamics, or the rescue of Sakura within the context of the fanfiction world.
You can try searching on popular fanfiction websites like FanFiction.net or Archive of Our Own (AO3). Just use the keywords 'pain kidnaps sakura' in their search bars and see if any relevant stories pop up.
It could be Naruto. Naruto has a strong bond with Sakura and would sense that something was wrong. He'd probably track her down using his amazing sense of smell or by asking around. Once he found Sasori, Naruto would use his Rasengan and his newfound Sage Mode powers to take on Sasori and rescue Sakura.
Sakura would likely be initially terrified but quickly regain her composure. She is a trained ninja after all. She might start by assessing her situation, looking for any weaknesses in Team Hebi's defenses or any possible escape routes. Sakura would also try to talk her way out of the situation, using her intelligence to reason with Team Hebi. If that doesn't work, she would be ready to fight back using her taijutsu skills and any medical ninjutsu that could be used offensively, like her chakra - enhanced strength punches.
Sasuke might also be involved in the rescue. Despite their complicated relationship, he still has some feelings for Sakura. And he wouldn't want to see her in the hands of someone like Deidara. Also, Kakashi, as their former sensei, would likely lead a rescue mission. He has the skills and experience to deal with Deidara's explosive attacks and find a way to save Sakura.
Well, one possibility is that Itachi has some hidden motives. Maybe he believes Sakura has knowledge about something important in the ninja world, like a secret jutsu or information about an enemy. So he kidnaps her to extract that information.
In some fanfictions, Sasuke could be under the influence of some dark power or curse. This power might compel him to kidnap Sakura. For example, a dark entity might want to use Sakura's abilities or her connection to Sasuke for its own evil purposes, and Sasuke, being unable to fully control himself, follows its commands.
It could also be a matter of desperation. Perhaps there is a threat to the village or someone she loves dearly, and she believes that Naruto holds the key to solving the problem. But instead of asking him directly, she kidnaps him in a hasty and ill - conceived plan. This could lead to a lot of drama and character development as Naruto tries to understand her actions and they both work towards resolving the real issue.
Perhaps in the fanfiction, Madara kidnaps Sakura because he realizes her potential as a medic - nin. He wants her to heal his old wounds or maybe study her unique healing abilities to find a way to make himself invincible. He could keep her in a hidden lair and force her to perform medical experiments on him.
Well, if Sasori kidnaps Sakura in fanfiction, it could lead to a really intense situation. Sasori is a formidable opponent. Sakura, on the other hand, has her medical ninjutsu skills and her growing strength in combat. She could potentially use her medical knowledge to her advantage. For example, she might be able to use some herbs or substances in the place where she's held captive to create a distraction or even a weapon. And there could be a rescue mission by her friends from Konoha, which would add more drama to the story.