In this fourth of a four part series, media artist Harun Farocki explores the interplay between modern warfare and electronic media using computer simulation and documentary footage. Originally presented as a simultaneous four-screen gallery video installation, the separate films are available exclusively on realeyz.tv. 　　Director's Notes to part IV: 　　“This chapter considers the high degree of similarity between the images used in briefing for war and those used in debriefing once it’s over. There is one difference, however: the program for recalling traumatic experiences is slightly cheaper. Here, nothing and nobody casts a shadow.” 　　(Harun Farocki)