As has been her habit since the death of her husband, the eccentric Marlies van Haesbergen does nightly rounds in the large office building where she resides. Her husband had been the building superintendent, and an apartment on the top floor came with the job. During one of her nightly tours, Mrs. van Haesbergen encounters Paul Vreeden, managing director of a multi-national dredging company, in the boardroom. He is sitting in his chair at the head of the table and she walks up to him. To her horror, she finds im dead. With the switchboard closed at night, Mrs. van Haesbergen rushes up to her apartment to call someone, but who? Deciding it is better to return to the board room to examine what exactly happened, she finds the man—the dead man—gone. Wrought with confusion, Mrs. van Haesbergen soon learns that Vreeden is on holiday in the Bahamas. With unbearable visions of the dead Mr.s Vreeden, she turns to Inspector DeKok for help.