Paul Quinn’s “This is My Father” is a haunting, heart-wrenching feature debut in which a lonely, middle-aged high school teacher (James Caan) embarks on a long-overdue search for the identity of his father. The chance discovery of an old memento of his mother’s sends him to Ireland, equipped with a decades-old photograph and the knowledge that he and his father share the same first name, Kieran. His presence on his mother’s home turf is not well-received. At first, the lack of memories about his mother seems a conspiracy, as if the small village in County Galway had something of which to be ashamed. When he pokes around the house of his mother’s childhood, the present owner throws him out, telling him his family has no claim on the property now. Only one old lady takes his search to heart — for a price, of course — and begins to weave him the tale of his birth. Told in flashback, it is a tale as passionate and doomed as “Romeo and Juliet,” complete with star-crossed lovers kept apart by the dictates of class and religion. This is also where “This is My Father” takes off. Photographed by director Quinn’s brother Declan (whose other camera credits include “Leaving Las Vegas”), the late-’30s-era village looks like a bit of heaven on earth. But it isn’t, particularly if you happen to be a poorhouse orphan in love with the daughter of a wealthy widow. As the original Kieran, Aidan Quinn gives the most affecting performance of his life. A strong-backed country boy, Quinn’s Kieran lives with and toils for the kindly tenant farmer couple (Donal Donnelly and Maria McDermottroe) who saved him from the orphanage years ago. When he falls for flashy Fiona (Moya Farrelly), the only child of the uppity Widow Flynn (Gina Moxley), no one is pleased. As the two carry out their illicit courtship, we root for them, hoping that they can overcome centuries of class distinctions and religious dogma. Yet, deep inside we know they are doomed. But even though the ill-fated romance is sweetly portrayed by Quinn and Farrelly, what’s most moving about the film is the accumulation of images and telling details. A tragic tale of epic proportions, the Brothers Quinn make “This is My Father” heartfelt and real by keeping it small. We never lose sight of the two lovers, who they are or more importantly, who society says they must be. A stage director before turning to film, Paul Quinn demonstrates his knack for dealing with actors. In addition to the wonderful performances by his brother Aidan and Farrelly, his cast boasts many fine supporting roles from such well-known Irish actors as Stephen Rea, Colm Meaney and Brendan Gleeson. On the American side, John Cusack turns in a fine cameo as a pilot and photographer who takes the only picture of the two lovers together. Caan also delivers a rare understated portrait of a man adrift, looking for an anchor on which to tether the remainder of his life. Despite the affecting central tale of doomed love, “This is My Father” has one gaping flaw: a parallel story involving Caan’s teen-age nephew, who’s accompanied his uncle to Ireland because he too is at a crossroads. While our intellect can accept this inconsequential secondary plot as merely a framing technique, our emotions see it differently. The scenes begin to rankle because we know if they weren’t there, we’d be seeing more of the two lovers. The story is lovingly photographed, acted and told, so it comes as no surprise when we learn that the story of “This is My Father” is a tale the Brothers Quinn grew up with. While our affection for it may not equal theirs, it is one we won’t soon