Mark Moskowitz’s “Stone Reader” is a charming home movie about the writer-director’s search for an elusive writer, but beneath a deceptively lighthearted surface it raises some serious questions about creativity, the power of writing and obsession. Though at over two hours it does seem a bit overlong, it’s a great literary mystery, as well as a declaration of a lifelong devotion to reading, and an investigation of why books hold such amazing power.

The crux of the picture is Moskowitz’s attempt to locate Dow Mossman, whose novel “The Stones of Summer” he first encountered but set aside back in 1972 and recently took up again. Falling in love with the tome this time around, Moskowitz was shocked to learn that Mossman had never published anything since, and attempted to track him down. Happily, as far as the film is involved, he took a decidedly circuitous route, first visiting various folks near his home base on the east coast–agents, literary critics, academics, people who’s attended the University of Iowa workshop at the same time Mossman was writing his novel there–and, while learning nothing specific about his quarry, engaging in plenty of illuminating conversation about writers in general (especially other one-time wonders), the vagaries of the publishing business, and the simple attraction of the written word and the process of reading. Even if the picture had gone no further than this and Mossman had remained an unattainable human Holy Grail, it would still be a fascinating piece, not least because of Moskowitz’s infectious enthusiasm for the chase and the questions he raises with the interviewees; but when things seem hopeless he decides to visit Iowa City himself, survey the “Mossman archive” in the university’s special collections room, and talk to whatever faculty might remain from the book’s time of composition. Without spilling too many beans, one can say that eventually there occurs a great “gotcha moment” that provides a satisfying resolution to the quest.

But as with so many chases, real and imagined, the joy of the one recounted in “Stone Reader” lies not so much in the way the race ends, but the territory one crosses while getting there. The final reel of Moskowitz’s film is all one could wish, but it’s the digressions along the way that give the picture real texture and intellectual richness. And the fact that Moskowitz himself is such an engaging companion makes it easy to identify with his drive to solve the Mossman riddle. You wind up wanting to take up “The Stones of Summer” yourself and discovering whether your reaction will be equally enthusiastic. (The book, long out of print, is scheduled to reappear next fall under the imprimatur of an organization called the Lost Books Club. You’d be wise to wait for it rather than plunk down the exorbitant prices now being charged for used copies of the original edition.)

“Stone Reader” isn’t really a documentary in the conventional sense. It’s more an example of film as personal essay, much like Michael Moore’s pictures. (In fact, Moskowitz’s search for Mossman even resembles Moore’s pursuit of Roger Smith.) But in this case the motive behind the search isn’t anger or making a political point; it’s the sheer love of reading, and the conviction that books matter as important influences in our lives. And ultimately even though its subject is an author who, from the purely practical point of view, was a “failure,” it proves an uplifting, even joyful, experience.