Harry Allen and Robert Van Gemert worked in procurement at Los Alamos during the Manhattan Project. In this interview, the pair discusses getting ready for the Trinity test, the challenges of using Jumbo, and how materials were transported safely and secretly in and out of Los Alamos. They remember helping to acquire the lead-lined tanks used to transport scientists to the blast zone after the Trinity test. Allen and Van Gemert also discuss the dormitories at Los Alamos, how the Town Council handled problems, and the secrets of PO Box 1663. They recall their interactions with leading scientists including Emilio Segre, Enrico Fermi, and Edward Teller.