David Moore is an electrical engineer. He lives with his daughter in a modest home in a small town. Moore conceives a new idea for a dry battery and drops all of his interest in the material things of life, such as earning a living. While absorbed in his invention, gradually his home is reduced to a hovel and his daughter has a difficult time trying to make two ends meet. Finally she is forced to stop caring for her father, who is by this time half-crazed, and seek employment. Because of her limited experience, she finds this difficult, but in a very romantic way she becomes acquainted with a young manufacturer. Although her work is not useful, he gives her work to take home and in other ways takes an interest in the gentle, frail-looking creature. The young manufacturer's interest in her takes him to her home, where he learns about her father and his invention. He now interests himself in the invention also and promises to take it to capitalists and engineers and have a test made as to the invention's commercial value. Not long after, the manufacturer learns that the invention is worthless. Knowing that this intelligence will break the hearts of both the inventor and his daughter, the manufacturer tells them that the invention is a success. He advances money to the pair and keeps them in ignorance of the true state of their affairs. They live happily and later the "old man" dies without learning that he has been living in a phantom paradise. His daughter, however, accidentally discovers that she has been receiving charity and tries to rebuke the manufacturer, but he tells her he did it all because he had learned to love her. She comes out of her phantom paradise and forever after lives in a real paradise.