Wealthy industrialist Lord Mullrine hosts a party at his mansion where he and the guests reenact the 1930s. The occasion is to celebrate fifty years since his company was founded with the late virologist Dr George McDee. Mullrine has even gone so far as to have every room in the house, with the exception of his private office, put back to its original style. Sapphire and Steel arrive under an alias, then, time itself starts to interfere. McDee turns up, alongsidr other anachronisms, and then, one by one, guests begin to be murdered — their bodies vanishing. Secrets and lies involving McDee and a marital affair from fifty years before are resurfacing, Time is playing a deadly game, and only Sapphire and Steel can end it.