Ao3 is gone.... I wanted to write a Fic about this but this will work I guess I'm going to write it later, But anyway crossover Gravity Falls and project Hail Mary, this is going to go great.
So the basic plot is Stanford Pines well traveling through Dimensions accidentally makes it onto Earid specifically in Grace's biodome which is lucky for him cuz he would have died otherwise.
Two nerds sitting a hot tub 10 ft apart cuz they're not !!

Star-and-World-Savior of Erid and Earth Doctor Captain Ryland Grace, and, Doctor Stanford Filbrick Pines