Rodolpho Aranda, head of an Argentinian chemical company, is found murdered in a Berlin bookshop: An elderly librarian named Valerie Steinfeld poisoned him with cyanide and then took her own life. As the LKA was unable to establish any connection between the victim and the perpetrator, the motive for the crime remains unclear. When Aranda's son Manuel arrives to transfer his father's body to Argentina, the case is officially closed. Instead of an explanation, the young doctor only receives a sealed zinc coffin - the search for the truth is left to him.
| Actor | Role |
|---|---|
 Heino FerchManuel Aranda | Manuel Aranda |
| DDennenesch ZoudéIrene Waldeck | Irene Waldeck |
 Judy WinterDoppelagentin Nora Hill | Doppelagentin Nora Hill |
 Wolf-Dietrich SprengerKriminalrat Groll | Kriminalrat Groll |
 Maria MägdefrauValerie Steinfeld | Valerie Steinfeld |
| EElisabeth RathMartha Waldeck, Mutter | Martha Waldeck, Mutter |
 Peter KurthGrant, US-Geheimdienstagent | Grant, US-Geheimdienstagent |
| NNadja BeckerLaura | Laura |
 Suzan AnbehYvonne | Yvonne |
| EEdgar M. BöhlkeRodolpho Aranda | Rodolpho Aranda |
| AAnnalena DukenNora Hill - 1944 | Nora Hill - 1944 |
 Christian PätzoldSiegfried | Siegfried |
 Götz SchubertLKA-Präsident | LKA-Präsident |