Having returned to the murder scene, Wozzeck becomes obsessed with the thought that the knife he killed Marie with will incriminate him, and throws it into the pond. When the blood-red moon appears again, Wozzeck, fearing that he has not thrown the knife far enough from shore and also wanting to wash away the blood staining his clothing and hands, wades into the pond and drowns. The Captain and the Doctor, passing by, hear Wozzeck moaning and rush off in fright.