Bring Down the Lights, Bring On the Narrator : THE FILM EXPLAINER. <i> By Gert Hofmann, translated from the German by Michael Hofmann (Northwestern University Press: $26.95, 250 pp.)</i>

Though few people know it existed, the craft of the film explainer, sometimes known as a film narrator or lecturer, was one of the more intriguing aspects of the silent film world.

Mostly in vogue before the circa 1910 appearance of inter-titles, the explainer would stand in front of an audience and talk viewers through the picture on the screen. These performers were especially popular in Japan, where they were known as benshi, and, according to Robert Sklar’s “Film: An International History of the Medium,” “some became more famous than screen stars and interpreted narratives and dialogue as it suited them.”

Creators of fictional material have from time to time found this profession irresistible. Toshiro Mifune had a cameo as a benshi in the American independent film “Picture Bride,” and a European narrator appeared in Israel Rabon’s striking Yiddish language novel, “The Street.” And now, in Gert Hofmann’s “The Film Explainer,” such a character comes out of the shadows and takes center stage.

We encounter Karl Hofmann in the early 1930s, when, as the film explainer for the city of Limbach’s Apollo cinema in the Saxony region of Germany, he is at the height of his powers and confident of the respect with which he’s treated in town.

“An audience needs someone to explain a film to them, at least its finer points,” he insists. “They have no idea what is contained in a film if you look at it closely, in every single shot. . . . That must be explained. Otherwise, it would be lost.”

Though his wife scoffs that “he’s not just an artist without any bread, he’s an artist without any art,” this film explainer is ideally suited to his profession. “Without cinema,” he says, “I would find life unendurable.” More than that, the explainer has no use for either nature or reality, fearing the latter and rejecting the former as “not sufficiently artificial for me.”

All this is seen and heard through the explainer’s grandson, who lives with the old gentleman and feels so close to him they often share the same thoughts as they walk side by side through town. (The explainer is called Grandfather throughout the book, and author Hofmann had a grandfather Karl who was a film explainer, adding a twist of memoir to the novel’s texture.)

Also factual are the dozens of silent films, complete with casts and years of release, that are mentioned as having been taken on by Grandfather Hofmann. Some are familiar, while others, like “The Indian Tomb,” “The Oyster Princess” and “The Eyes of the Mummy Ma,” are notable more for their evocative titles and their exotic scenarios.

Those story lines turn out to be the closest thing to a gripping plot “The Film Explainer” has. An extended character study, this lucid yet elusive novel collects the moments in one man’s life and then stands back to allow them to be added up.

Critical to this process is the period the story covers, a time when not only the Apollo cinema but society itself begin to tatter and disintegrate. Always somewhere in the background are Adolf Hitler and the collapse of the Weimar Republic, visible in thrown-away lines like the note that the price of an outfit of clothes was “reduced to 39 billion marks.”

That backdrop becomes foreground at roughly the same time as sound finally comes to Limbach in the guise of “The Jazz Singer.” Insisting that “people want to see film actors who do their own talking,” the Apollo’s Jewish owner cuts the explainer’s work week down to two days, then one day, then to nothing at all.

Grandfather takes this demotion hard at first, collapsing and wasting away. What finally revives him is a sudden interest in the doings of the Nazi Party, and “The Film Explainer” artfully invites us to watch a character we’ve liked subtly become one we don’t.

Gert Hofmann died in 1993 but, continuing the novel’s family connection, “The Film Explainer” was translated from the German by Gert’s son Michael Hofmann, himself a respected writer. The translation was well-reviewed in England, where it won the prestigious Independent Foreign Fiction Award and was interpreted by critics as a parable of Germany between the wars.

It’s not necessary to see things that way to enjoy this poetic and philosophical novel, but care must be taken with its off-center style, simultaneously straightforward and elliptical. As much as anything else, “The Film Explainer” is about the creation of mood, which puts it in perfect sync with the silent films its protagonist loved to pieces.