Sally Lindsay is Jean White, the British ex-patriot residing in France along with a group of other Brits. Last season she became engaged to Dom (Steve Edge) after their relationship finally became public. They are celebrating their first Christmas together but things don’t go according to plan. What is meant to be a festive occasion turns into a nail-biting experience.

It’s Christmas Eve and Jean, Dom, along with Jeremy and Judith (Robin Askwith and Sue Holderness), the quaint, quirky, and rich couple, as well as several others, are invited to a special evening at the local museum. It promises to be overflowing with champagne, to the delight of Judith, and include a surprise reveal of the museum’s new acquisition – a rare Ormolu box once owned by Marie Antoinette. Jean is there to use her skills in antiquities to verify the rare box is indeed the one once owned by Marie Antoinette.

When she opens the box, she discovers a ticking bomb. This is not what anyone had in mind when they received the invitation to this event. When the group attempts to exit the building they discover all the doors and windows are locked, trapping them all inside with the bomb about to go off.

That’s not the worst of it. They also discover the security guard has been murdered, and she was the only one who knew how to open the security doors.

They then find a riddle inside the box addressed to Jean. With her knowledge of all things from the past and present, she goes to work trying to unravel the riddle. The answer is the key to stopping the bomb.

Now it is a race against time as Jean thinks she has the answer but must locate the specific art object which is somewhere in the building. The piece of art should be enough to solve the riddle and stop the bomb. Everyone sets out to look for the piece and with time ticking away, they must hurry through the building with limited knowledge of the many pieces of art, but armed – no pun intended – with a clue from Jean.

Meanwhile, Police Chief Caron (Alex Gaumond) has figured out there is something amiss inside the museum and manages to contact Dom who informs him of their dilemma. As Caron attempts to find an access route into the building and those inside trying to find the answer to the riddle, the timer on the bomb is ticking down.

Can they crack the code to stop the bomb? Will Caron find a way inside the building to save the trapped people? Will it be a happy Christmas for everyone?

As viewers wonder if Caron will get there first or if Jean will solve the riddle to disable the bomb, they know at least some of those trapped will make it out alive, as it is no secret season five will begin airing in 2026. But that is no guarantee that all of them will make it out alive. And, as they all find out, there is a murderer amongst them, making the final 90 minutes until explosion that much more stressful and filled with uncertainty and anxiety.

This two-part ‘Madame Blanc Mystery Christmas Special’ sets up a storyline that will continue in the new season. This is a fun and compelling series with interesting characters and a viewership that has anxiously been waiting for the next installment.

Part 1 of the Christmas Special premieres December 15, 2025 with the finale premiering December 22, 2025. And the finale introduces a mystery that will continue to play out next year in Season 5.