What Is The Fed's "Doomsday Book"?

Thanks to a FOIA request, an internal document from the Federal Reserve, known as the "Doomsday Book" has been released. The purpose of it is to guide The Fed's actions during emergencies. Emre Kuvvet, professor of finance at Nova Southeastern University says "the central bank—or at least the legal team at its dominant member bank—apparently believes it can rely on precedent to justify virtually any emergency action." Do laws lose their purpose when virtually anything can be justified? Perhaps Tacitus was right: "The more corrupt the state, the more numerous the laws."