“THEME SONG FOR AN OLD SHOW,” By Jeffrey Lewis, Other Press, New York, 2007, 149 pages, hardcover, $22.95.

Jeffrey Lewis, in the third novel of his “Meritocracy Quartet” (after “Meritocracy: A Love Story” [2004] and “A Conference of the Birds” [2005]), has found the perfect vehicle for writing about middle age, that period in one’s life that often progresses in fits and starts, when we second-guess ourselves, when we’re unsure of our focus, when we try – often unsuccessfully – to find coherence and purpose.

The narrator of “Theme Song,” Louie, has left a very successful career in television to write four books, each one about a decade in his life: the 1960s, when he was in college; the ’70s, during one movement or another; and now, with this book, the ’80s, when he and his friends deal with success, failure and aging.

Sound familiar? Jeffrey Lewis, who spends much of the year in Castine, left Hollywood (as a writer and producer of “Hill Street Blues”) to write his “Meritocracy Quartet”; one of the challenges (and rewards) of this book is the necessary work of separating writer and narrator, a task accentuated by the similarity of the author’s last name and the narrator’s first, and by Lewis’ decision to present “Theme Song” as a novel in progress.

As Louie struggles with the shape of the book, the plot and characters emerge: his father, who left Louie’s mother and moved to California in the 1950s; his wife, Melissa; his friend and collaborator Zacky; and his Yale classmates Adam and Teddy. “Theme Song” is not a book where shots ring out; driven by an attempt to make sense of the times and to understand his father, Louie reminds himself at one point, “More plot, more business.” The narrative is often interrupted by edits, by second thoughts, by reflections on what he has written, by false starts.

The central focus of his book continues to elude Louie; he rejects first one character and then another, until we begin to see the direction in which he’s headed: It is, after all and above all, a book about what happens to us as we approach the midpoint in our lives. His parents are separated, his father with a new wife and family; friends divorce; his marriage is no Hollywood romance (“still Melissa did not leave,” Louie periodically mentions, and we’re as surprised as he seems to be); people die; parents age.

It’s also a novel about television and the great changes that took place during the ’80s. Louie tells us his program, “Northie,” “was realistic, surrealistic, tragic, comic, tragicomic, or way over the top. Certainly it took a lot of chances.” Louie becomes rich and famous. He uses his power to help his friends and to confound his rivals. Just when he seems to have found the key to the novel – “envy and television and the new rich” – he decides to focus instead on his friend Teddy. Not before, however, in a burst of self-hatred, he laments that all he seems to be writing about is “‘I’ ‘I’ ‘I’ ‘I’ ‘I.'”

Louie begins the last section of the book by noting that it’s “[t]ime for the plot to show its final shape.” Significantly, the title of this last section is “Fathers and Sons.” But Louie’s father has been at his shoulder all along. First separated by the width of a continent, then by the bitterness of Louie’s mother, then by the seesawing of success in the same profession, then by … whatever it is that almost always separates men from their fathers. Louie notices for the first time his father’s frailty (“Where had he gone to, or had he always been that way?”), and then, in that role reversal that happens to so many of us, he becomes the comfort giver, the one who kisses his father’s forehead before himself going to sleep.

Inevitably, however, Louie comes to understand that his novel needs to go even further, beyond his father to his own “ongoing effort to understand and forgive, to be a man, and not a bigger man than [his] father was, but just a man, a little bit taller than he or a little bit shorter.” A certain amount of self-absorption, to be sure, but knowing ourselves demands time spent gazing inward.

“Theme Song for an Old Show” is a theme song for the oldest show of all – discovering what, besides mortality, we share with all humans, and also what makes us individual. Jeffrey Lewis has written a novel the very form and structure of which helps us to see life’s journey.