What happens to the parents in film insidious?

In the film "Insidious," the parents, Josh and Renai Lambert, face escalating supernatural events that threaten their family. After their son Dalton falls into a mysterious coma, they discover he is trapped in a realm called The Further, leading them to confront malevolent spirits. Ultimately, Josh becomes possessed by a malevolent entity, which complicates their efforts to save Dalton and reunite the family. The film concludes with a lingering sense of dread about the unresolved supernatural threats they face.