The large canvas represents one of the crucial episodes of the myth of Perseus, son of Zeus and Danae, told in the fifth book of Ovid's Metamorphoses, in which he saves Andromeda, his wife. However, the woman had been promised to Phineus who, to avenge her refusal, bursts into the wedding banquet with a host of warriors. Perseus, represented here on the right, defends himself from aggression by exposing the head of the Gorgon Medusa, who petrifies enemies with her eyes. In front of him is Phineus who tries to protect himself with the shield. At his feet are some of his fallen followers and in the background the terrified guests who cover their eyes to escape the spell. The imposing composition by Luca Giordano, signed on the first step at the bottom left, is full of scenographic inventions and theatrical effects, such as the two columns in the center of the scene with a dark red cloth wrapping around them, useful for dividing the scene.