Introduction
The following is an edited version of an article which was originally published in 1947 Yearbook of the Norwegian Tourist Association. The author, who was a member of a Norwegian sabotage team, has authorized its inclusion in Studies in Intelligence. The sabotage operation against the German heavy water production plant was celebrated in a movie, “The Heroes of Telemark. ” Mr. Helberg, who participated in the operation, is still hearty. In 1990, he took a member of the Editorial Board of Studies in Intelligence on a trip to Vemork, retracing part of the journey described in the article.