“Niagra, Niagra” begins quietly in a drugstore in Poughkeepsie, where Marcie, the film’s disarming heroine, likes to shoplift. She literally crashes into Seth, a quiet outsider, also on a shoplifting…

Set in 19th-century Russia, Allen is a cowardly serf drafted into the Napoleonic war, who would rather write poetry and obsess over his beautiful but pretentious cousin. Allen’s cowardice serves…