“Threshold” is the story of a former concert pianist struggling to free himself from a self-imposed exile inside his dark, austere apartment. Briggs hasn’t been outside in four years. Haunted by the tragic death of his daughter, he lives each day exactly like the preceding one, compulsively performing his daily routines-making his meals, scrubbing the floor, writing in his notebooks, as well as playing Jenga with an odd visitor named Heaney, who never tires of hounding Briggs about his shadowy existence. On this particular day, all the pressures on Briggs-his terrifying dreams, another testy encounter with Heaney, the ominous, periodic ring of the telephone, plus the devastating memory loop playing in his head-combine and push him to the breaking point. Will he be able to make his peace with the past, and take that first step across the threshold, back into the light?