Bess is the daughter of the landlord at the inn, but he has locked his inn up so that nobody can enter. The highwayman who comes to call can't get to Bess, his beloved, but she can still communicate to him because he can see her at her window. She is plaiting or braiding a love knot into her black hair to signal her love to her highwayman. She then opens the window. He wants to kiss her, but the best that she can do is let her long black hair tumble down so that he can kiss its perfumed waves. He promises that no matter what, he will come back for her.
Unfortunately, King George's men are hunting for the highwayman and tie Bess to a bedpost with a rifle under her arm, planning to pull the trigger and kill the highwayman when he comes back. Bess thwarts them by being able to loosen her bonds enough to get a finger on the trigger and aim the gun at herself, warning her beloved off by killing herself.
Ironically, if the highwayman had not been able to see Bess braiding the crimson love knot into her hair and had not been able to smell and kiss her hair, he might not have returned that night, and she might still be alive.