(Note that this is not mine, and if you're confused about anything you can just ask me about it.)
Phineas and Ferb is an original cartoon on Disney Channel, created by Dan Povenmire (you know, that guy who used to work on Spongebob and Family Guy) and Jeff Marsh. What isn't known about the series is that both creators widely hate Disney's monopoly and the show's real concept goes beyond just a children's cartoon; an episode about Dr. Heinz Doofenshmirtz's real concept was produced secretly by good part of the staff who ran the risk of being fired without thinking twice, even the original voice actors.
The episode leaked of where they kept it by an anonymous who uploaded it on a little trendy cartoon forum.
That day my computer was doing an annoying noise like if it were a whisk. My big brother insisted to check it up or the CPU was going to literally burn up. Anyway, I got into that forum where the thread posted by a relatively new user posted the lost episode, I had some time to download it before having to go to my grandparents' house. We got back at 1:00 AM. My dad was drunk, my mom forced him to sleep in the sofa and my brother was "having some fun" with the hooker he has for a girlfriend, saying that he had something important to do to avoid having to go with my grandparents. Whatever. As soon as I got home, I started the episode and as expected my computer kept making that noise.
The episode was called "The Horrible Death of Phineas" and according to the summary, this is an alternative episode to the one where they're caught and send to the Smile-Away summer camp.
In this episode, it is shown as a common Phineas and Ferb episode, cheerful, nice, cute and begins with Phineas and Ferb having Isabella's troop to help them pimp-up the car to make it fly and to build the airport tower. This time, a huge crowd is present to witness this masterpiece.
Meanwhile Perry the Platypus is called by Major Monogram to fight Doofenshmirtz, but it doesn't sound funny or anything. He tells Perry that he must stop him but doesn't explain why. Once he goes to stop Doofenshmirtz to his headquarters, the doctor explains that he's truly fed up of being treated like that, that all his plans go wrong and he is planning to kill everyone using a real atomic bomb. Then Doofenshmirtz draws a real gun and opens fire against Perry, who is forced to run away because he can't fight him while he has the gun. The gun is able to hurt, as it makes holes in the lair's walls and ceiling. His escape follows with a totally complete demented and cruel, red-eyed Doofenshmirtz, who had an angry expression, which was rather terrifying and scary. He had gone mad!
He chased Perry during a short but sadistic sequece and Perry is almost killed, but luckily manages to dodge the shots. When they get to Phineas' backyard, Candace drags Linda to see Phineas and Ferb's invention as in every episode, then Phineas walks towards his mama to show her the flying car, but in that exact moment Doofenshmirtz opens fire and Perry dodges the bullet, and a slow motion sequence is shown how he accidentally shoots Phineas and when it hits him, everything turns black and white and "Hide and Seek" by Imogen Heap plays. Phineas is lying in the lawn, but with a puddle of his own blood drawn in the habitual Phineas and Ferb style. The video goes back to the colors when Phineas is in the lawn and it is noticeable: a bright red puddle of blood. The crowd glares, horrified at Doofenshmirtz, and the scene cuts abruptly after showing Phineas lying over a puddle of his own blood, staring at the sky. It's there act one ends.
Act two starts with a funeral, and now everything seems extremely depressing. The mortuary is mostly black and the stained glass windows, which enlighten the room, are a depressing monochrome tone. Candace, Linda, Lawrence and Ferb look very forlorn, the explorer troop laments as well, and the camera focuses during two insufferable minutes on Isabella crying inconsolably. It sounded real, as if the voice actress was actually crying to make this scene. Candace, in extreme grief, regrets about this while furiously hitting Phineas' coffin, crying that this wouldn't have happened if she didn't try to catch them. Act two cuts abruptly to black.
Act three beings with a label "Two Days Later..." on which Phineas' house is seen from the outside, but it's cloudy and gloomy. Candace is in her room, extremely stressed, with a rigid smile and hanging a rope in the ceiling while humming the Beatles' song "Yellow Submarine". Jeremy happily enters to the house through the backyard, goes to the kitchen and after offering condolences to Linda, he asks for Candace. Linda happily tells him that she's upstairs.
But when Jeremy enters to her room, he sees with horror that Candace hanged herself and died a few minutes ago. Jeremy takes down the corpse and passionately kisses it, but then Linda enters to see if everything is alright and after seeing this, screams "Jeremy...how could you?" thinking that Jeremy choked her to death.
After that, we cut to a scene where both Phineas' parents, Ferb, Isabella, Baljeet, Buford, Doofenshmirtz's ex- wife Charlene, his daughter Vanessa, Major Monogram, Carl and Perry are in a prison's electric chair room with Doofenshmirtz in it. All of them have twisted and sick smiles with the purest, unhealthiest, sadistic joy. He begs for mercy but then Major Monogram orders to proceed with the execution. Perry, smiling in a sick and morbid way, swtiches on the chair. Right before his death, a sequence of real photos can be seen, showing a man wearing a lab coat with a little girl playing and walking in a park, although those actors don't look like Doofenshmirtz and Vanessa, but they clearly represent them. After that, the last thing he sees is Vanessa kissing passionately with her mother. It was so incestuous-lesbic that I puked on my keyboard.
Doofenshmirtz finally dies brutally: electrocuted on a slow, lethal voltage to lengthen his suffering. At the end, Ferb says something like "Irony is cruel, but not as much as hell."
The episode ends with Doofenshmirtz's lifeless body being thrown on a pile of decaying corpses, among which Jeremy's is still fresh.
The next morning, I looked again for the episode, Google shown among other undesired results the same forum, but the user was banned and the file possibly no longer exists.