Maybe Spider - Man is trapped in an alternate dimension where his powers don't work properly. The Avengers discover this and use their technology (like Stark's portal - creating tech) and superpowers to break into the dimension and save him. Once saved, Spider - Man joins them on a mission to stop the source of this dimension - trapping problem which could be a new, menacing enemy that the Avengers and Spider - Man have to face together.
In this fanfiction, Spider - Man could be poisoned by a new type of venom created by a villain. He's slowly losing his strength and abilities. The Avengers find out and rush to help. Hulk might use his strength to carry Spider - Man to safety while Black Widow and Hawkeye cover them. Dr. Strange could then use his magic to extract the venom from Spider - Man's body, thus saving him. After that, Spider - Man teams up with the Avengers to take down the villain who created the venom.
The plot might involve Spider - Man getting into some trouble in New York and the three Avengers coming to his aid. It could be that a powerful alien artifact has been stolen and Spider - Man accidentally gets blamed for it. The Avengers then step in to help clear his name and find the real culprit while also protecting the city from the potential danger of the artifact.
Well, one possibility could be that Spider - Man is mind - controlled and ends up attacking the Avengers. Maybe a villain uses some sort of advanced technology or magic to make him do it. He might be forced to use his web - slinging and super - strength against his allies, causing harm both physically and emotionally to the Avengers and their fans who look up to their unity.
One possibility could be that the Avengers capture Spider - Man because they suspect he has been influenced by some sort of mind - control or dark magic. Maybe they think he's a threat to the city without realizing he's actually trying to help. Another could be that there's a misunderstanding in which Spider - Man's actions are misinterpreted as being against the Avengers' interests.
Well, one possible plot could be that there's a misunderstanding. Maybe some bad guy has framed the Avengers for something really bad, and Spider - Man, believing the false evidence, decides to take them on. He uses his agility and web - slinging skills to surprise the Avengers at first. But as the fight progresses, he starts to realize that something is off and that they might be innocent.
One possible plot could be that Spider - Man uses his agility and spider - sense to detect an enemy that the Avengers have overlooked. For example, he might notice some hidden Chitauri technology that is about to activate and cause chaos. So he swings in, warns the Avengers, and then together they figure out how to disable it.
One possible plot could be that Spider - Man gets accidentally transported to the Avengers' headquarters. He has to prove himself to the Avengers at first, since they don't really know him well. Then, they discover a common enemy that is planning to attack both New York City (Spider - Man's territory) and other major cities around the world that the Avengers protect. Together, they combine their powers and skills. Spider - Man's agility and spider - sense work well with Iron Man's technology, Captain America's leadership and combat skills, Thor's godly strength, etc. They have to overcome their differences in fighting styles and strategies to defeat the enemy.
Another possibility is that the Avengers are being manipulated by a villain. The bad guy could be using false information to make the Avengers believe that Spider - Man is a danger. So they go after him without really knowing the truth.
One possible plot could be that Spider - Man and Natasha start off as friends within the Avengers. They go on various missions together and gradually develop feelings for each other. Their relationship might face challenges from other Avengers who are initially skeptical. Maybe they have to overcome a powerful villain while also dealing with their budding relationship.
One reason could be a misunderstanding. Maybe some events were misinterpreted, and the Avengers thought Spider - Man was involved in something bad. For example, if there were some crimes that seemed to have Spider - Man's fingerprints all over them, but in reality, he was being framed.
One possible plot twist could be that the Avengers mistake Spider - Man for an enemy at first. Maybe they see him using his powers in a way that seems suspicious. Then, as they start to fight, they realize he's just a young hero trying to do good. Another twist could be that Spider - Man has a secret connection to one of the Avengers, like he's related to Tony Stark in a way no one knew. This would add a whole new layer to their interactions.