ok so basically the theory is that Sal and Travis are cousins. HEAR ME OUT Y'ALL. Diane Fisher (Sal's mother) and Kenneth Phelps (Travis' father) are siblings. Diane is from Nockfell and left the cult before marrying Henry and conceiving sal. After Diane's death, Henry moved back to Nockfell because it's her hometown and he wanted to feel closer to her in a way. It also makes sense as to why Kenneth tried to kill sal as a child (and ended up killing Diane), not only because he's the only one that could stop the cult and yadda yadda yadda, but also because he's the son of his sister who betrayed him by leaving the cult.
