A Secret Revealed is a non-canon video that can be unlocked in God of War, specifically by beating the game on Spartan Mode. It shows the origin of Kratos, a child born out of wedlock in a small village. Shunned by their people due to wild rumors, Kratos and his mother, Callisto, fled to Sparta to start a new life. Kratos eventually became captain of the Spartan army, and left his mother behind.
Years later, Kratos visited his mother and attempted to discover the identity of his anonymous father. Before she could reveal to him who his father was, she changed into a horrific monster. Driving his blade through his once mother, with her last breath Kratos is told his father was Zeus. Kratos decided to take his revenge on Zeus for having abandoned him and his mother. This may be one of the many reasons why Kratos hates Zeus so much, aside from the events that lay the foundation of the story in God of War II. The video was later recycled for use in God of War: Ghost of Sparta.