We were motivated to return to the morphosyntax of adverbial participles in Russian at this time for two reasons. First, new Russian data have come to light whose diagnostic potential was not recognized in earlier work (see section 4.2). Second, Williams' 1994 theory of theta roles, predication, and binding enables us to propose an analysis of the syntax of adverbial participles that is truly minimal since it makes it possible to replace empirically unmotivated underlying syntactic structures with simpler, more explanatory ones. We argue that the combination of Williams' theory of vertical binding and the data involving the case agreement of contrastive sam and odin in adverbial participle phrases makes an important contribution to our understanding of the structures and rules involved in the derivation and control of nonfinite verbal categories. However, we do not claim to have accounted for all the uses of adverbial participles in Russian; as we see in section 5, there remains a range of phenomena that are not well understood. However, since our theory accounts for the canonical data of standard Russian in a highly explanatory way, we believe that it is essentially correct and can serve as the basis of a unified analysis of control phenomena. Our goal in this paper is thus twofold: first, to present our analysis of adverbial participles in standard Russian (sections 1-4) and, second, to point out uses of adverbial participles in standard and nonstandard Russian that do not appear to be consonant with our theory and to suggest how these data might be assimilated to the theory or how the theory might be changed to accommodate the data (section 5). The advantage of an explicit theory applied systematically to the full range of data is that it provides both new solutions to old problems and, equally importantly, it raises new problems based on old data that were erroneously thought to be well understood. Below we demonstrate that our analysis