...all the cool things that happen in every Pixar movie come from one source of magic. And that source is...

"Brave" takes place in the Dark Ages, far before any other film in the Pixar Theory timeline. It also introduces magic to the universe through a mysterious witch (who will be important later on). 

This magic, powered by closeness to humans, can bring inanimate objects to life, turn people into animals and turn doors into magical portals.

"The Incredibles" happens next in the Pixar Theory timeline, maybe in the 1960s. In the movie, the government uses human "energy" to create artificial intelligence. That energy, Pixar Theory says, is the magic left over from "Brave."

The movie also introduces the Buy N Large company (BnL), which will be very important going forward.

These stories happen next, according to Pixar Theory.

According to the Theory, these BnL-built toys get their energy from humans -- another remnant of the magic left over from "Brave."

According to the Pixar Theory, animals use the same "Brave"-era magic that toys do, once again because they're near humans.

For example, Dory can read and communicate because she grew up around humans. 

This is the next one in the Pixar Theory timeline. Again, we have an animal who comes in contact with humans and is, or becomes, really smart through their friendship. Pixar Theory once again credits "Brave"-era magic for that. 

The growth of tech company BnL is a good way to track the Pixar Theory timeline. In "Up," BnL has grown so much that the company can kick Carl out of his home. 

But that's not the only clue that the Pixar movies are in the same universe...

"Toy Story 3" is full of hints that all Pixar movies are connected. Andy receives a postcard from "Up" characters Carl and Ellie, Boo from "Monsters Inc." appears as an older child in daycare (confirmed by Pixar) and Darla from "Finding Nemo" is on the cover of a magazine.

Also important to the theory is the scene where Buzz takes out his batteries, which have a BnL logo on them, confirming the company's growth.

According to the Pixar Theory timeline, BnL has both taken over and trashed the planet by the time "Wall-E" comes along. 

The Pixar Theory actually places the Cars franchise after "Wall-E," when humans are gone. That same "Brave"-era magic is still lingering, though, which is why we have talking cars all over the place.

Without humans and the magic they enable, Pixar Theory says, the cars eventually die out. That leaves...

At the end of "Wall-E," BnL's cleanup finally ends and humans return to Earth. They show up just in time for...

Yep, the talking bugs come after the apocalypse. The return of humans spark life in insects and birds -- that same magic from "Brave" again!  

This part of Pixar Theory comes from some DVD extras. Here it goes: Monsters aren't really monsters; they're a human-animal hybrid that emerges far in Earth's future. 

Humans have died out, the theory says. However, monsters still need "Brave"-era magic to live, so... 

The monsters must travel to the past through door-portals (sound familiar?) to collect energy from a time when humans still existed. 

At the end of "Monsters Inc.," the monsters learn that joy is a more powerful emotion than fear, which theoretically ends the Pixar timeline in a moment of happiness and harmony between humans, animals and technology.

Yes, human love is original magic from "Brave" that keeps this whole timeline together.  

However, according to Pixar Theory, this is when the timeline collapses in on itself. When Sully goes back into time to collect human energy and accidentally reveals himself to a little girl named Boo, he changes everything.

What's the next story? The first story, according to Pixar Theory.

It's theorized that as Boo grows up, she cannot forget the "kitty" who appeared to her through a portal door. She grows into a powerful witch. Trying to track down Sully, she goes in and out of history through those magical portal doors.

Why do fans think this? The witch from "Brave" can use magic portals, and she has items from throughout history in her house. Cross-movie Easter eggs can also be interpreted as Boo leaving clues throughout history as she travels through time. And if you look closely you can even see a drawing of Sully, etched into her things.