The Sesemann Frankfurt Residence is both a formal household governed by Fraulein Rottenmeier’s rules and the enclosed setting of a mystery that its residents cannot explain. Its locked front door repeatedly stands open by morning, turning corridors and rooms into spaces of unease; the eventual discovery that Heidi has been sleepwalking shifts the house’s alarm into urgent concern for her health and return home.

Rooms, Corridors, and Growing Alarm

As twilight fell, Fraulein Rottenmeier began moving through the house warily, looking behind her and into dark corners as though someone might be following her. She would not go alone to the upper guest chambers or down into the large council-chamber, where footsteps echoed beneath portraits of solemn old senators in broad white collars. Tinette, Sebastian, and John likewise sought one another’s company when sent to distant parts of the house, each invoking the need for help with something to carry. The cook, who had served there for years, could only shake her head over her pots and kettles.

The servants’ apprehension had a concrete cause: each morning they found the front door wide open, though no intruder could be seen. At first they searched every room and corner for a thief, but nothing had been taken. The door was secured with two locks and a wooden bar, yet it stood open again the next morning. The adjoining houses remained shut, and the household, despite rising earlier, never caught the opening in progress. The unexplained breach made the residence feel vulnerable even while its occupants slept behind locked doors.

The House Under Watch

After persuasion from Fraulein Rottenmeier, Sebastian and John agreed to keep watch in the room beside the council-chamber. She supplied weapons belonging to Herr Sesemann and a bottle of spirits to fortify them. Their vigil was itself unsettled: the cordial first made them talkative, then sleepy, and John proved difficult to wake when midnight came. In the stillness, Sebastian listened and tried to rouse his companion. The watch illustrates how the mystery had altered ordinary household routines, drawing servants into a fearful attempt to guard a house whose doors seemed to open without explanation.

Fraulein Rottenmeier had initially withheld the story from Clara and Heidi, fearing that telling the children would mean they could not be left alone. When she finally explained the apparitions, Clara became frightened and proposed that the household sleep together with a light burning, while Tinette stayed nearby and Sebastian and John watched in the hall. Heidi, by contrast, said she was not afraid of the ghost and would rather sleep alone than have Tinette in her room. In the residence, fear was therefore unevenly experienced: the supposed haunting alarmed the adults and Clara, while Heidi did not share their fear of ghosts.

Revelation and Departure Decision

The doctor identified Heidi as the source of the nightly disturbance: she was a sleepwalker who had been opening the front door. He also told Herr Sesemann that Heidi was suffering severely from homesickness and had become dangerously emaciated. In his judgment, the same remedy addressed both the sleepwalking and the child’s condition: she needed to return to her native mountain air. The residence’s apparent haunting was thus resolved not as an attack from outside, but as a sign of Heidi’s distress within the household.

Herr Sesemann was shocked that Heidi had become ill under his roof without anyone recognizing what was happening. Though he initially resisted sending her away in such a weakened state, the doctor’s warning persuaded him that she could not safely remain. He ordered the household to prepare for an immediate journey: John was to get the horses and carriage, Tinette was to wake and dress Heidi, and Sebastian was sent to fetch Dete. Fraulein Rottenmeier was instructed to pack Heidi’s belongings and a substantial part of Clara’s clothing so Heidi could travel properly supplied. The residence that had spent nights trying to keep a mysterious danger outside its doors now organized itself to send Heidi home, recognizing that her need was to leave.