Phryne, Dot and Dr. Mac happily accompany Aunt Prudence to a picturesque chalet to celebrate a white Christmas in July. The party arrives to find one of the residents dead - electrocuted while hanging festive lights. No more suspicious than the usual Miss Fisher investigation, until the body count starts to rapidly rise. Heavy snowfalls and harsh weather trap them all with a murderer in their midst - and any one of them the next victim. It's a race against time for Phryne and Jack to hunt down the culprit - and restore enough Christmas joy to take full advantage should they find themselves standing under that bunch of that mistletoe!