Like other Indian commentators, the great Advaitin Śakara (eighth century CE) engages throughout his works with 'fictive opponents' and their ideas, considering their views, subjecting them to criticism and establishing his final position in response to them. Normally he does this with politeness if with vigour. However, in his commentary on the voluminous Bhadrayaka Upaniad, there is one set of opponents whom he treats rather differently, subjecting them to invective at every turn. It seems, at first sight, that they are the trkikas (logicians). This gives us a puzzle. The most obvious reference of the term 'trkika' is to members of the Nyya school, which specialised in forms of argument and prama theory. Indeed, some translators and commentators assume that this is who Śakara has in mind here. But this is not how he normally treats Naiyyikas. In this article, I subject Śamkara's texts to close reading to try to discover who these elusive people might be, using clues from register theory to help develop my argument. I suggest a particular identification for them which helps us to understand the context in which Śakara was teaching, a context in which rivalries between ritualist brahmins and growing devotional movements may well have affected the way he was trying to position his Advaitin tradition. © 2011 The Author.