N0,7 Morse investigates the death of Sylvia Kane, an 18-year-old woman found dead in a pub car park, where she was late in meeting her date. In her possession is found an envelope with a secret-coded-message addressed to the dead woman's co-worker Jennifer Coleby, who has secrets of her own. Several relationships and connections are established by Morse & Lewis to find the truth about how Sylvia died.