Barbara (Marianne Faithful) settles down to marry a boring, buttoned-down schoolteacher after a torrid love affair with Daniel (Alain Delon). A student with penchant for motorcycles, Daniel turns Barbara on to bikes and lovemaking. He gives her a motorcycle so she can leave her sleeping husband and restart their passionate, erotic, adulterous affair. Clad in skintight leather, Barbara has erotic and psychedelic flashbacks and flashforwards as she races her bike to be reunited with her illicit lover.