The title of the film, set in Luxembourg in 1942, during the Nazi occupation, amalgamates the words Schacko (helmet) and chapeau claque (opera hat). The village, in which it is set, has not yet been feeling the effects of the war at this point.

A devil is shown as an attraction at a funfair, where he asks a visitor to free him. The man sneaks back in the evening, lets the devil out and takes him home...