If you make a character throw another character into a door, then the thrown character will be inside the door and able to walk straight through it.
Not sure if it only works for doors, or if it works for walls as well, because to be completely honest I was too lazy to find an appropriate wall that would actually let me walk to the other side. All the walls in the area I'm in are pretty much directly next to doors, or right at the edge of the map. The video shows me throwing a character into an undiscovered door (I know it's there because this isn't my first time playing this part, but my characters didn't see it), and shows me moving my character to the other side, where I shouldn't be.
