“What’s ur opinion on the tapestry hanging in the Northwest mansion?“ 

IT CAME OUT PRETTY NICE, DONT YOU THINK? THE NATIVE PEOPLE OF GRAVITY FALLS REALLY HAD A FLARE FOR CAPTURING MY TRUE ESSENCE. ALTHOUGH THEIR TIMING ON PROPHECIES LEFT SOMETHING TO BE DESIRED! GOTTA HAND IT TO THAY SHAMAN THOUGH, HE WAS A REAL FUN GUY TO TALK TO, EVEN IF HE TURNED OUT TO BE LESS COOPERATIVE THAN I HOPED. HEY, THERES ALWAYS THE NEXT GENERATION..”

Alright, so I think the reason as to why the author stopped trusting bill is because he found those old paintings in a cave from the natives of Gravity falls.

And it must be something like Bill destroying the world or apocalyptic, or even the natives revering him hundreds and hundreds-thousands maybe?- of years ago. Anything like that, but their timing was off so maybe the author thought it would destroy the world when the portal first opened, when the author himself planned to open the portal maybe? And therefore “there’s always the next generation”, and not to mention the tapestry, which shows that the Northwests are hugely connected to bill, or at least aware of him and his power.

The Northwests, being tied up in their own conspiracy and all, are NOT the type of people who would hang this without knowing what it meant in my opinion. 

I don’t think they’re decedents of the shaman because those would’ve been native people and Gravity Falls was actually founded back in colonial times by Quentin Trembley, and the Nortwests came after him but they know because they would’ve found those cave drawings right? They would’ve seen the tapestry or the drawings and they would’ve tried to find out why that triangle with an eye was so important in this land they were making their home. And maybe back when the mansion was being produced they had the scriptures and put the tapestry with their findings and because they “created” Gravity Falls when there were still natives in that land they had someone who spoke the language or knew the stories and they just–

They knew about him they knew he existed and that Gravity Falls was his playground but as time passed they stopped CARING and focused on their own ghost issue and their wealth and it became a children’s story, one people stopped putting merit behind, one they stopped telling because it wasn’t as important. They forgot and they didn’t prepare their young for the future. 

So when the author found those drawings on the walls he knew he knew Bill was more than he signed up for and he knew that the Northwests knew about him, but they didn’t tell anyone, they didn't warn anyone. He could have found their “Cipher File” knowing they didn’t use it and kept it in secret, using it to find ways to stop Bill or to further his warnings and protecting the future of Gravity Falls, his home.

Seeing those things he knew he couldn’t escape Bill but he could stop him and warn whoever found the journals against him. So everything became codes and invisible ink. 

That’s why there’s always that “more than it seems” impression from the series that’s why the eye with the “x"through it is so important. 

sees it all its beyond their knowledge it’s more than what they perceive to be true.

 There’s more to what goes on than just gnomes and multibears there’s more than summerween and mini golf gremlins there’s something evil. Waiting. There’s something big out there in Gravity Falls, something Bill wants to let loose so he can hang back and watch the world BURN.

SPECIAL THANKS TO poeticpines. FOR HELPING ME WITH THIS THEORY AND BEING MY BRO