Mute and adopted Dipper pines ( BillDip)

Dipper "Pines" is the mute and adopted brother to Mable Pines Dipper became mute after his first family abused him at a very early age. He was too young to have that much pain so he just stopped talking. After the Pines family adopted him he was much more happy but Dipper has never said a word to them. when they go to Gravity Fall and meat Bill what will happen when Dipper makes a deal with Bill to save his friends and family?