Greek Mythology at his finest and with some effort to reveal what is going on in this painting. There is one significant object in this painting that makes us aware of its meaning.
We see Hercules, swinging a large bat, on the edge of murdering Cacus. Cacus, an ancient Roman god, a thief also who stole some cattle from Hercules. He dragged the animals into his cave and was discovered and murdered.
A clear and direct inspiration was the woodcut and engraving by Hendrick Goltzius of the late 16th century. This artwork is an almost identical copy of the pictured.