An epic family feud is erupting pitting son against father on the eve of a new book about the Church of Scientology.  Church leader David Miscavige is threatening to sue the U.K.  publisher of his father’s book coming out next week entitled  “RUTHLESS: Scientology, My Son David Miscavige, and Me”

Ron Miscavige chronicles his son’s journey within Scientology, starting when the family joined in 1970, and then his ultimate rise to current leader of the church. It is a rare look inside Scientology told by someone who lived it for more than 40 years before breaking away in 2012.

Ron Miscavige who describes his son’s leadership as “brutal” sat down for an exclusive interview with ABC’s 20/20 airing Friday night at 10 on CHCH.