Sin.

There is a legend of an old Hartz tower
That tells of one, a noble, who had sold
His soul unto the Fiend; who grew not old
On this condition: That the demon's power
Cease every midnight for a single hour,
And in that hour his body should be cold,
His limbs grow shriveled, and his face, behold!
Become a death's-head in the taper's glower.
So unto Sin Life gives his best. Her arts
Make all his outward seeming beautiful
Before the world; but in his heart of hearts
Abides an hour when her strength is null;
When he shall feel the death through all his parts
Strike, and his countenance become a skull.