The chapter proposes an account of epistemic indefinites cross-linguistically, focusing on the case of German irgendein and Italian un qualche. Four main functions for EIs are identified initially: specific unknown (SU); epistemic unknown (epiU); negative polarity (NPI); and the deontic free choice (deoFC). It is subsequently observed that while irgendein qualifies for all functions, un qualche qualifies only for the first two. The second part of the chapter proposes an account of these data in the framework of a Dynamic Semantics with Conceptual Covers. Our point of departure is the assumption that epistemic indefinites are existentials with two additional characteristics: (i) they induce an obligatory domain shift and (ii) they are felici...