The holiest night, the loneliest people. A singer, a killer and Santa Clause. United in their destiny.

General Heinz Büchner is in charge of a special unit of the German army. His son Christopher is a member of the unit. They get the mission to take out a band of terrorists that plan an attack on the American headquarters in Heidelberg.

After her second failed marriage, laundry owner Jule seeks advice from radio presenter Ariane. Her call-in show is running out of listeners, but Jule turns out to be a savior: she has fallen in love with a man eleven years her junior, and now half the town is watching spellbound to see how the relationship develops. When Ariane realizes that Jule's teenage crush is her son, she does everything she can to sabotage the relationship.

The firefighter Erik wants to make a proposal to his girlfriend Sofie, but at the crucial moment sparkles the attractive Melissa in between. When Sofie learns that Erik had a fleeting affair with Melissa on Carnival, a world collapses for her. But the two gather again, as Erik promises high and holy that such a thing will never happen again. To underline the seriousness of his intentions, he makes her an unconventional offer: he "gives" her an infidelity. He should not have done that, because suddenly he threatens to lose Sofie to his best friend.

The successful journalist Linda (Thekla Carola Wied) depends on their job to the nails to finally spend a quiet life with the retired Latin teacher Jacob (Günther Maria Halmer). But yet they have reckoned without their busy adult children Leonie (Julia Brendler) and Thomas (Jens Atzorn) made the constantly unload their triplets care with grandparents. Then, when even a previous love of Thomas Jakob is around the corner and another grandson in his luggage, the pensioner is finally overwhelmed. He does everything it can to keep the delicate origin of the baby a secret. Finally, Thomas and Leonie want to soon give the knot.

Linda Rosenau cares only about her job. As editor-in-chief of a successful women's magazine, she must always stay at the top edge. There is hardly time for her adult daughter Leonie and her three little grandchildren; the stressed-out Leonie has to go to hospital after a fainting spell and Linda has no choice but to take care of the babies - which, as it turned out, are the result of a one-night stand. Father of the children is untraceable, but Linda senses the grandfather of the cute triplet in the widowed teacher Dr. Jakob Buchmann...