The book, Vows of Silence, is an account of the child abuse scandals during the years of papacy of John Paul II.
The first part of the book deals largely with diocesan instances of abuse and the very slow coming-to-terms with it that occurred in the American Church and in Rome. It does cover details about the shock and resistance both here and in Rome, during the reign of Pope John Paul II, that prevented resolute and rapid resolutions. The book is well-researched and footnoted and this is valuable information going forward.
The latter part is predominantly about the Legionaries of Christ and its affiliated groups, including Regnum Christi. The behavior of Fr. Marcial Maciel Degollado, the notorious founder, is well-covered. I've read a lot about this topic over the last couple of years, but what Jason Berry has here is a very good summary. I've also had some exposure to Regnum Christi, so some of this information was new to me and some wasn't. I'd recommend these chapters on Regnum Christi to anyone coming into proximity with them in any way.
However, mixed in with all the really well-documented detail is a lot of intra-organizational polemics that the reader has to watch for. When reading this, it's wise to remember that abuse occurred across the interpretative spectrum within the Church.
There were abusers in "progressive" enclaves, abusers in "traditional" enclaves, abusers in idiosyncratic small groups, and abusers among individual members of clergy. The commonality among them all was the psychological morbidity seen in these men, rather than in their ecclesial or political views. Many of them were sociopaths, pure and simple. The group dynamics involving these men were usually also shocking and immoral.
Trying to build a workforce of priests without also drawing covert defectives, with tendencies towards setting up immoral or psychologically warped arrangements for themselves, is a problem for any large organization like a Church, particularly since until just recently people didn't expect to see this kind of deviancy in clergymen, and it routinely "flew under the radar," so to speak. This is the sad story of the Catholic Church's coming to terms with flowery assumptions and the deviancies and criminality that those assumptions can conceal.