Avid readers of Robert A. Caro may greet his new book, “Working: Researching, Interviewing, Writing,” with a mixture of excitement and trepidation. On the one hand: Another Caro book, and it’s not a biography! On the other hand: Another Caro book — and it’s not a biography?

Considering that the 83-year-old averages a book a decade, his fans might wonder whether “Working” will reset the clock that started in 2012, when the fourth book of his multivolume magnum opus, “The Years of Lyndon Johnson,” was published.

No need to worry, though this assemblage of personal reflections and interviews may give the true Caro completist a creeping sense of déjà vu. Much of the material was either published before or distilled from stories Caro has recounted elsewhere, and the book reads as if it were designed to divert as little of his time as possible. (Caro says he has a “full-scale memoir” planned, to be completed after the next Johnson volume, though at his age, he says, he can also “do the math.”) Small and charming at about 200 pages, a quick spritz instead of a deep dive, “Working” is like the antithesis of Caro’s labor-intensive oeuvre, making it strangely reassuring proof that he is, well, working.

[ “Working” was one of our most anticipated books of April. See the full list. ]

The next Johnson book will be “the fifth of a projected three volumes,” he writes, declining to get into specifics (“My writing seems never to come out well if I’ve talked about it beforehand”) while promising that it will be the final installment. That means it will have to cover, among other things, the presidential election of 1964; Johnson’s Great Society programs and his continuing feud with Bobby Kennedy; the passage of the 1965 Voting Rights Act; the decision not to run for re-election in 1968; Martin Luther King Jr.’s assassination; Bobby Kennedy’s assassination; and Johnson’s post-presidency life until his death in 1973.