"Greasy Lake" has a number of themes, including the journey to the dark side, the thrill of adventure and masculine violence. The narrator of the story emerge from a long night having confronted the death that awaits wanton behavior, realizing he has control of his life via choices he makes.
The narrator and his friends are first motivated by the desire to act bad, beyond their usual practical jokes. As the night goes on, they nearly kill a man and rape a woman, discovering a thin edge that separates a violent thrill from violence itself. The narrator eventually sees a corpse, facing his own mortality and his fate if he does not return to making better choices.