“This is the most thoroughly researched and articulately presented book of its kind. Whether you are a Sedevacantist, or researching the movement, this book is irreplaceable. Brilliant!” 
Director of Apologetics and Evangelization
Tim Staples calls brilliant a book that heretically explains:
a. How the Church can be heretical by law and decree.
b. How the pope can lead the Catholic Church into heresy and error.
c. How anyone, including the pope, can publicly, repeatedly, and knowingly reject the Catholic Religion altogether and still be a member of the Church.
a. The Catholic Church is spotless in all her doctrines, laws, decrees, and liturgies. (Popes St. Zosimus, St. Hormisdas, Pius IX, Leo XIII, Pope Pius XI, and Pius XII.) 
b. The Pope guards the Church from all heresy and error. He doesn’t and can’t believe, instigate, lead, or promote heresy and error against the Faith. (Pope Leo XIII.) 
c. Only those are to be accounted really members of the Church who have been regenerated in the waters of Baptism and profess the true faith. (Pope Pius XII.) 
Salza/Siscoe and company utterly reject the above three Catholic beliefs. Apparently, Tim Staples does too.
Further reading: The Anti-Sedevacantist Syndrome
 Pope St. Zosimus in Quamvis Patrum traditio 409 AD, Pope St. Hormisdas in Libellus professionis fidei 517 AD, Pope Pius IX in Quanta Cura 1864 and the First Vatican Council, Pope Leo XIII in Satis Cognitum 1896, Pope Pius XI in Quas Primas 1925, and Pope Pius XII in Mystici Corporis Christi 1943 and Haurietis Aquas 1956.
 Pope Leo XIII in Satis Cognitum 1896.
 Pope Pius XII in Mystici Corporis Christi 1943.