This is one of three engravings in a series called Meisterstiche. The others are Melancholia I and Saint Jerome in His Study.
The engraving is dated 1513, two hundred years after the dissolution of the Knights Templar in 1313. The S before the date may be an allusion to the Greek sigma, of numeric value 200, but others say it is Samekh, one of the 22 paths on the Qabbalistic tree of life. Seems to me that a lot of engravings are signed S. for Scuplt., after the Latin for engraving, and that’s a lot simpler of an explanation.
We see a skull in the bottom left corner; the night in full armour (shining armor?) carries a lance; behing him is a pig-snouted horned devil and he is passing Death on his pale horse, who is carrying an hourglass. Under the knight’s horse runs a long-haired retriever, a hunting dog.
Dürer called this picture Reuter, which is, Rider.