Invited to spend the holidays at an English country house, the famous Belgian detective becomes caught up in a glittering mystery when a priceless jewel connected to the family’s festive celebration disappears and a string of curious visitors and disguises raises suspicions. Against a backdrop of yuletide cheer, simmering resentments and theatrical misdirection, he teases out false alibis, hidden motives and surprising tenderness, ultimately exposing the clever plot and recovering the missing gem through calm observation and a well-timed revelation.