The following story tells the details of the ketone body metabolism, focusing on the needs of the brain in prolonged fasting conditions. This literary composition highlights the use of ketone bodies as an important metabolic adaptation that avoids excessive protein degradation and allows for greater survival. The liver produces ketone bodies that are released into the bloodstream and exported to the brain, which then absorbs and transforms them into acetyl-CoA. These molecules with central role in metabolism generate energy through the Krebs cycle, electron transport chain, and oxidative phosphorylation. This tale is a valuable tool for biochemistry teachers and students because it can help with a deeper understanding of the physiological roles of ketone bodies and their metabolism.