The Russian Sleep Experiment, posted to the Creepypasta Wiki in 2010, takes the form of a fake report claiming that the old Soviet Union used an experimental gas to keep five subjects awake for fifteen days. The subjects’ horrific deterioration over time is recorded like a dry observational log.
The power of this tale lies in its form. Instead of screaming or exaggeration it borrows the flat, clinical style of an experiment record to create the realism of reading actual documents. The way an objective, report-like surface amplifies the horror demonstrates exactly why documentary horror works.