This paper motivates and develops a semantics for indicative conditionals, as well as other epistemic vocabulary. If we start by studying the behavior of simple nested epistemic modals, we can naturally build a theory that explains the interaction of epistemic modals and indicative conditionals, together with other distinctive linguistic data not sufficiently appreciated by extant semantic accounts. The semantics I defend constitutes a dramatic alternative to standard truth conditional theories, as it assigns sets of probability measures rather than sets of worlds as sentential semantic values. I argue that what my theory lacks in conservatism is made up for by its strength; combined with a novel pragmatics, my semantic theory can account for the distinctive and suggestive data collected here.