Idioms of the Torlak dialect (spoken in southeast Serbia and western Bulgaria) are known for their “double affiliation”. On the one hand, by virtue of their historical and phonetic features, they belong to the western range of the South Slavic dialectic continuum. On the other hand, according to their morphosyntactic characteristics (the presence of the post-positive article, the reduced case system, etc.), they adhere to the eastern range (i. e. Balkan Slavic). This paper views the innovative features of Torlak syntax from a strictly synchronic perspective and as a phenomenon of double (i. e. both head- and dependent-) argument marking. It is argued that cases of double argument marking in Torlak appear when several conditions are met. In order to be archaically marked with an overt relict case marker, a nominal group should either refer to the a-declension or, in case of the other declension types, assume a prominent position not only on the animacy scale but also on the scale of emotional involvement. In order to be innovatively indexed by a bound personal form (Haspelmath 2013), the argument should create the most favourable pragmatic and semantic conditions for the possible (optional) occurrence of argument indexing, i. e. be a derhematised and highly individualised Patient.