The suicide of the great abstract expressionist Arshile Gorky in 1945 hangs over his surviving family: his cosmopolitan widow “Mougouch” and his two daughters. This moving, penetrating documentary, made by his granddaughter Cosima Spender, is both a brilliant portrait of the artist — a man who told myriad lies about his true identity — and the haunted tale of a family still grappling with his turbulent ghost. Ranging from London to New York to Gorky’s native Armenia, Spender’s intimate, honest film transcends the usual boundaries of the art documentary: it’s as special as the mythic, larger than life man it brings into clear focus.