A lonely government clerk - shy, awkward, blundering - finds himself pursued by a mysterious stranger. Somehow he looks familiar. In fact, he realizes, he looks exactly like him. He even has the same name. But, unlike him, he is charming and confident. Soon the stranger starts insinuating himself into his life. He works at his office, stays at his apartment, ingratiates himself with his colleagues. No one seems surprised. Who is he? What does he want? Is he a double, or something darker altogether?