Goldfish

When Gertrud, the belowed mother of twins Agnes and Otto suddenly dies, their father August is unable to accept it and tell the kids she is actually on vacation. The lie seems to work, but as soon as other members of the familiy die, he has to readjust it to protect the children from the cruel truth of death. The years pass and it will be too late when August realize the children had not just discover his lie but improved it. - IMDb