In which lil Paulie is a pyromaniac in development and Stu is a frustrated older brother trying to keep him alive.
Pre Hamburg days, where John leads his Quarrymen as more of a gang than a band, and Paul's this starstruck little bugger who never seems to leave them alone. John grows sort of attached to him, finds him adorably naive yet also very talented, gifts him a lighter when he starts smoking.
Paul takes the gift as if it were a holy item or something, and slow but surely grows obsessed with flames and setting things on fire, almost as much as he's obsessed with John.
Obviously it's an unrequited emotion: John's not only too old for Paul, he also mocks him ruthlessly for being queer, despite his own repressed queerness ((can you say, 'internalized homophobia'?)).
Anyways, Paul breaks down because John was, like, his first big love. And since he has no idea what to do with all those emotions, he starts setting shit on fire continuously.
This whole time, John's best mate Stu has sort of kept an eye on Paul, mostly because he knows John's the kind of dick to illusion young kids (usually birds, though) and then break their hearts, and he caught glimpse of something dangerous on Paul when he first met him, wouldn't want him to go nuts over his first rejection.
So. Paul's heartbroken and hurt and out for flames, Stu's exhausted and has no idea how to hold him back from destroying everything, John's just sitting back and enjoying the shitshow he's made.
It becomes serious when Paul's teenage angst bullshit reaches critical levels and he starts a fire at Strawberry Fields, John's very personal hang out spot and place of childhood memories. Basically Paul makes a funeral pyre for the love he felt for him, burns all the cheesy letters and silly love songs he wrote him, and then the fire goes out of control. No one gets hurt, but half the fields are entirely burnt down.
John's righteously pissed that Paul would do that to a place that means so much to him, Paul's actually traumatized because he wasn't expecting it to go so far, and in the end someone has to take the blame.
Stu takes one for the team and his already bad reputation from being a teddy boy and a somber artist expands to include 'arsonist'. The things he does for this stupid child...
Paul rids of his lighter in the Mersey later on, scared of what he's done with it, of the consequences, of someone finding the truth out and mostly just wanting to forget it all.
Police actually holds Stu for a couple days, but since they cannot prove he started the fire nor have the means to investigate who did, they let him go, so Paul disposing of the lighter is an actual smart move.
So. John and Paul have this fallout, and John surely tries to get Paul in trouble, but being the problematic manchild he essentially is, no one quite believes him. Paul's just got a better reputation, y'know?
Paul still makes a point of looking for Stu and thanking him for taking the blame, which Stu brushes off as long as he promises not to do it again. Paul agrees.