NEW YORK -- A niece of Scientology leader David Miscavige (mihs-CAYV'-ij) is planning a tell-all memoir about the church.

Jenna Miscavige Hill has been a frequent critic of the Church of Scientology since publicly breaking with it in 2005. She has a deal with HarperCollins Publishers imprint William Morrow for "Beyond Belief: My Secret Life inside Scientology and My Harrowing Escape."

Morrow announced Monday the book will come out in January. It says the 28-year-old Hill will reveal "strange and disturbing" details about growing up in the church and will provide a firsthand account of Scientology's "upper ranks."

David Miscavige chairs the board that oversees the church, founded in the 1950s by science fiction writer L. Ron Hubbard.

Scientology teaches followers they're immortal spiritual beings who live on after death. Church members include Tom Cruise and John Travolta.