Synthesizers also figured prominently on the 1984 follow-up, "Das Buch", which courted trouble with the censors on the song "Ich will nicht vergessen" (I Don't Want To Forget), and its references to "Deutschland," a taboo in the GDR, which the band explained as a reference to Heinrich Heine, although the more immediate referent was divided Germany ("Denk' ich an die Leute, drüben und hier", I think of the people over there and here). The title track, essentially a monologue set to music about a book on another planet describing a post-nuclear-war Earth, featured a Free German Youth choir. The band, who except for Scharfschwerdt were now in their 40s, declared they would play until their "Rockerrente" (Rocker's Pension) in the prophetic song of that name.