Everyone is wearing a poppy for remembrance, which should give you a clue that this episode will concern the past and the sins committed then. It also concerns a murderer who is very much present in the minds of Morse and his colleagues, and who plans to continue murdering in the future unless they can stop him.
Time is of the essence in “Sway.” The endlessness of time; mathematical infinity; ouroboros, the snake that devours its tail, symbolizing eternity...
Time; and possibly the Rolling Stones, although I’m not certain about the last part.
As the episode begins, a newspaper headline trumpets the case of the moment: “Woman Strangled – Oxford housewife willingly opened door to killer.” This refers to the murder of Anne Curran Matthews.
At the office, Morse is typing up a report for Chief Superintendent Bright concerning the “amalgamation” of police stations. This might pose a problem for Morse in the future, but it’s certainly not enough to occupy all of his intellect right now. He’s turning over the Curran Matthews case in his mind and associating it with another open case. They’re not identical, but there are similarities.
Moments later, another victim is found. Vivienne Haldane, the wife of an Oxford professor, has been strangled with a silk stocking. (“Not hers,” says Dr. DeBryn.) Physical relations had taken place within an hour or two of death. (“Nothing to say ‘unwillingly,’” says Dr. DeBryn.) And the pieces begin to fall into place for Morse.
There are now three cases involving women who were strangled with silk stockings. More specifically, married women who spend most of their time apart from their husbands and who weren’t wearing their wedding rings when their bodies were found.