Treasures abound in Heritage Hall, which houses the College and Seminary archives as well as the archives of the Christian Reformed Church in North America. Currently on display are some artifacts from the Diet Eman Collection. They include photos of Deit and her fiancé, Hein Sietsma, who eventually died in the concentration camp in Dachau in 1945. Diet herself was sent to Scheveningen Prison near The Hague for her activities as a Dutch Resistance worker. She wrote Things We Couldn't Say, which tells of the work she and Hein undertook to combat Nazi persecution in the Netherlands. Hekman Library has copies of this memoir in English, German, and Dutch.

An excerpt from chapter six: "By 1943 the group we worked with needed over eight hundred [identification] cards every month. The men from the knokploeg did that work, and of course it was very dangerous. But they did it for good reason, not simply because it was high adventure. I went to a few of their planning meetings, and those men always got down on their knees first to ask God to protect and help them..."