Esther Roloff, a probationary insurance investigator from Wattenscheid, is asked for help by her brother Olaf. His colleague Boris Bäcker has mysteriously disappeared after a visit to the new Lütgen casino. Olaf believes that the casino is involved, and the mountain of debt left behind by the local reporter speaks volumes. However, Esther soon becomes suspicious: not only were Bäcker's gambling debts cleared before his disappearance, but he was also working on a dossier about a man whom he believed had committed a murder.