Tourists from all over the world look at the mummy of Junker Friedrich von Kuhlbanz in the village church of Roggelin with shuddering curiosity. Apparently the terrible oath that the Junker swore 300 years ago has been fulfilled: I will not rot in my grave if I committed the murder of the shepherd Dühn. The Köhler family from Berlin inherited the old, run-down inn opposite the Roggeliner Church. Mother Renate is developing into a committed innkeeper and her son Marco has no objection to the move either. Only his older sister Maja can't do anything with the "village goths" and would like to be back in Berlin. That changes with a test of courage that she owes Torsten, the mayor's son. At midnight she suddenly appears in the crypt opposite the real Junker Friedrich von Kuhlbanz.

Not only Maja is interested in the mummy, but also a supposedly English lord named Coolberry, who hired the taxi driver Pacholke. Coolberry pretends to buy Kuhlbanz in order to allegedly transfer him to the crypt of his ancestors. Much to the annoyance of Uncle Hermann, who as grave digger and crypt guardian has a special relationship with the old mummy and also suspects of its nightly activities. There is additional excitement when Marco rings the church bell at an unusual time. Old Hanne in particular interprets this as a bad omen. Friedrich assures Maja that he did not commit the murder of the shepherd Dühn, and Maja decides to help him. She wants to prove his innocence.

At the community council meeting, Maja can just prevent the mummy from being sold to Coolberry. She can also win over Uncle Hermann in her search for the truth. What really happened on the night of the murder 300 years ago? There is an encrypted note in the church book and Maja and Friedrich uncover a secret. At the opening ceremony of the inn, Torsten tries again to land with Maja. But her thoughts only revolve around Friedrich. Torsten's father seems to have better luck, whose preference for Renate is met with earthly reciprocation.

Although old Hanne warns Maja not to get involved with Kuhlbanz, Maja calls the shadow court to prove Friedrich's innocence. Just before midnight, she rings the bell. The cemetery begins to live, dark figures slowly rise from the graves - the shadow court can sit. Friedrich gets justice. He is acquitted and the real killer is exposed. But it almost seems as if the happy ending is missing.