midnight
`` Then your theory is that some sort of a ray machine was put in operation before the helicopter landed ? '' `` It is too early to attempt any theorizing , Carnes . Let us confine ourselves to the known facts . Lieutenant Breslau was normal at midnight and was working in this room . Some time between then and seven this morning he underwent certain mental and physical changes which prevent him from telling us what he observed . During the same period , a hole was cut in the roof and things of great importance stolen . At the same time , all the glass in the laboratory became semi-opaque .