Back, he spurred like a madman, shouting a curse to the sky, With the white road smoking behind him and his rapier brandished high!
When he hears how Bess died, the highwayman makes a dumb move. He goes back.
The speaker makes it clear that he's almost crazy with sadness and anger. He curses and rides as fast as he can, swinging his sword as he goes.
Blood-red were his spurs in the golden noon; wine-red was his velvet coat, When they shot him down on the highway, Down like a dog on the highway, And he lay in his blood on the highway, with the bunch of lace at his throat.
Then (you guessed it) the highwayman dies. He gets shot down by the British soldiers.
We get lots more little refrains in these lines including reminders of what the highwayman is wearing (like in lines 7-9).
We also hear that he is shot "down like a dog." Sharp poetry detectives will remember that the speaker used that same word to describe Tim, the crazy ostler, in line 24. Maybe there's a connection there. Maybe Tim had something to do with the highwayman's death? Any thoughts?