On 5 July 1942, Margot Frank, Anne’s sister, received notification that she was to be sent to the East for work. The family knew that this meant deportation to a concentration camp and saw no other option than to go into hiding. Earlier than planned, Edith, Otto, Anne and Margot hid themselves in the rear building at Prinsengracht 263 in Amsterdam, where the Dutch offices of the Opekta firm were located. Their hiding place became a refuge for a total of eight people, with the Frank family being joined there by Hermann and Auguste van Pels with their son Peter and by Fritz Pfeffer.