Velma couldn’t speak because her brain was damaged purposely during the transfer. After Annette had her husband extract their brains, he successfully swapped their minds. It was a huge risk, but they had to take it.
Annette’s 40-year-old body wasn’t just overweight. She was suffering from chronic back pain and terminal pancreatic cancer. They didn’t have any time to waste with aggressive cancer treatments, so Xavier decided to do the unthinkable.
Of course, they wouldn’t tell Velma any of this. It wasn’t like she was going to be able to understand. And it wasn’t like she’d be able to convince anybody to help her. All Velma could do was stare with her frantic and confused eyes while Annette hugged her young body.