Forgive this old warhorse of a trope — there are two kinds of non-fiction writers in the world: those who are writers who happen to dig exploring the real world and those who are researchers who happen to know how to write standard English sentences. Bill Bryson, whose charming A Short History of Nearly Everything is a primer both on how things and words work, is an example of the former. Andrea Rock, whose The Mind at Night: The New Science of How and Why We Dream is a dry read about a lush subject, is a textbook example of the latter. It’s not that the information Rock presents isn’t interesting. During her foray into the science of the sleeping brain, she uncovered some fascinating tidbits about competing theories, some of which pit Freud against pretty much everyone else, as well as details about how the mentally ill mind dreams and why dreams seem to be needed. Not all of Rock’s information is new, despite the promises of the subtitle. Really, this collection of chapters collects and attempts to synthesize both recent and historical data. Most of the nuggets presented in Mind at Night have been nibbled by other journalists as well, such as the theory that the sleeping brain is engaged in risk-free problem solving and the proof that lucid dreaming is doable by the average sleeper. Despite the relative lack of startling new material, the ideas themselves are still interesting.