When you're writing a novel about serial killers, how far should you go in your research? Do you have to think like a serial killer? Do you need to find the emotions and the skills of a serial killer to ensure your character works on paper? In "Psiko: Pencuri Hati", these questions consume the main character Sidi. Sidi is a writer, whose wretched soul is always struggling internally, tries to find some quiet time whilst doing research for his latest novel about serial killers, but finds himself succumbing to the darkness, little by little.