Eight-year-old Nina loves Christmas. It's best when her patchwork family of thirteen celebrates together - just like last year, when her new grandma was still alive. Things don't look too rosy for the approaching festivities, as the pre-Christmas meeting between the seven adults ends in an argument.

Leipzig, December 1734: Christmas brings the Bach family together. The first snow has fallen and the children Gottfried and Elisabeth are delighted about the arrival of their older brothers Friedemann and Emanuel. The Thomaskantor has retired to his music room. Anna Magdalena supports her husband, as there are only a few days left and his latest work, the six-part "Christmas Oratorio", must be finished on time. It is awaited with suspicion by the city council and the gentlemen of the consistory, who have long found Bach's waywardness a thorn in their side and fear that, after the premiere of the St. Matthew Passion a few years earlier, the St. Thomas Church will once again be filled with "operatic" music. With the oratorio, Johann Sebastian Bach hopes that he will finally become court composer in Dresden. And, as always, he demands that all members of the family join forces to help him. But differences of opinion are increasingly delaying the completion of Bach's most famous work.

A dream come true for Martha, Mikkel, and Mats: they get to celebrate Christmas in Sommerby. They travel together to visit Grandma Inge, with their parents planning to join them shortly before Christmas. But then everything turns out differently than expected...