A chance encounter means Luther might be on the verge of finding love. But nothing comes easily - not when a fetish killer is on the hunt, not when an internet tormentor has had the tables turned and not when his worst enemies are his own colleagues.
Luther discovers the fetish killer is reenacting the past. Can he stop him before he kills again? Meanwhile Ripley has to choose whether to turn a blind eye to Luther's unorthodox policing or betray him on record.
The Doctor and the Ponds puzzle over an unlikely invasion of Earth, as millions of sinister black cubes arrive overnight, almost like presents falling from the sky.