In the novel The Mirror Crack'd from Side to Side, Reingarden Studios is the photographic studio in the United States where Margot Bence received her training as a professional photographer under the tutelage of one Andrew Quilp. This fact and the fact that Bence lived in US town of Seven Springs led Inspector Craddock to hazard a question to Bence that she perhaps knew Marina Gregg better than she had cared to admit. In this he was proven right.