Not satisfied with ordinary masturbation, a young woman looking for something more exciting to do masturbates on the train, without panties or bra, in broad daylight. The tension of not knowing when or who might see her gets her excited, and she goes from masturbating secretly to masturbating with a vibrator, and finally masturbating with her fingers. What's more, she shows off her masturbation to other passengers, pressing her breasts against them, and even negotiating for sex...