This article discusses the literary representation of the "concentrationary universe" in the works of Yehiel Dinur, the Yiddish and Hebrew author who published under the pseudonym Ka. Tzetnik. He became known to the public on the witness stand of the Eichmann trial in 1962. Ka. Tzetnik's novels Salamandra, Piepel, and House of Dolls are read in this article within the context of the polemic over the Jewish victims' alleged collaboration with the Nazi annihilation system—a polemic generated after World War II by Bruno Bettelheim, Raul Hilberg, Hannah Arendt, and others, and revived by Primo Levi in his last book, The Drowned and the Saved (1986). Contrary to previous readings of Ka. Tzetnik's oeuvre, this article presents it as a unique, daring, and nonjudgmental literary testimony to the "inside" of the Lager as a gray zone, a testimony that defies Levi's distinction between "the drowned" and "the saved." Ka. Tzetnik's emphatic representation of existence in this "situation at the limits" is understood in relation to works by such authors as Jorge Semprún, Charlotte Delbo, Ida Fink, and Tadeusz Borowski.