Away! The foul fiend follows me! Through the sharp hawthorn blows the cold wind. Hum! Go to thy cold bed and warm thee.
– William Shakespeare
King Lear, Act 3, Scene 4. Edgar enters disguised as the madman Poor Tom and speaks about the devil following him. The talk of the "foul fiend" is Edgar acting mad, but it also refers to Edmund who haunts Edgar and is taking his place as his father Gloucester’s heir.