When Arnold, an introverted and compulsive runner, begins to admire a mysterious female runner called Helena, he is is more than happy to be a silent voyeur. Yet when Helena starts to approach him, he can barely resist her appeal. Gradually though, Helena begins to reveal that there is something sinister that subverts her voluptuous beauty. As the tension between the two builds to a climax, Arnold must forego his timidness and confront whatever lurks behind Helena's outward veneer.