It’s a haunting yet natural question: what exactly happens to the human body after death? YouTube creator @Zackdfilms explores this in a simulation that breaks down the stages of decomposition in fascinating—and chilling—detail.

Within the first 24 hours after death, blood begins to settle in the lowest parts of the body due to gravity, creating purplish-red discoloration known as livor mortis. This is commonly seen on the back when a body is lying face up in a coffin.

As the days pass, bacteria and internal enzymes begin breaking down the body’s organs. Before that happens, however, trapped gases cause the body to bloat. This bloating can be dramatic and is one of the early visual signs of decomposition.

After a few weeks, the internal organs and soft tissues, including the eyes, begin to liquefy. The eyes, in particular, often melt completely, which many viewers found to be the most unsettling part of the process.

Eventually, the skin begins to peel away, and all soft tissue continues to degrade. Depending on burial conditions, full decomposition takes years.

According to Daniel Wescott, director of the Forensic Anthropology Center at Texas State University, a body in a coffin can begin decomposing within a year. However, full skeletonization can take up to ten years.

Nicholas Passalacqua of Western Carolina University adds that if a body is buried without a coffin, the process may be faster—usually around five years.

In the end, only the bones remain, a quiet testament to the passage of time and nature’s reclaiming process.