Introduction and Outline I will argue that cases of massive deception, such as new evil demon cases, as well as one-off cases of local deception, present challenges to views according to which epistemic reasons, epistemic warrant, epistemic rationality, or epistemic norms are factive. In doing so, I will argue that proponents of a factive turn should observe important distinctions between what are often simply referred to as ‘bad cases’. Recognising epistemologically significant differences between deception cases raises serious challenges for proponents of a factive turn. Here is how I will proceed. In Section 6.2, I consider various cases of warranted false beliefs. These include probabilistic cases and cases of one-off perceptual illusions. I note that resisting a factive turn in epistemology does not involve any commitment to epistemic internalism. On the contrary, a combination of moderate externalism in epistemology and philosophy of mind provides a unified externalist motivation for assuming that agents who are prone to one-off deceptions have a warranted false belief. I also critically discuss the frequently invoked terminology of ‘good cases’ and ‘bad cases’. In Section 6.3, I argue that the appropriate epistemic diagnosis of massive deception cases depends on the specific aspects of them. Specifically, I argue that massive deception cases may be specified such that the agent is unwarranted according to the unified mind/epistemology externalism. Thus, I argue that it is consistent with a unified externalist methodology to accept that massively deceived subjects are unwarranted without adopting the more radical view that warrant is factive. In Section 6.4, I note some general ramifications and raise some challenges for proponents of a factive turn. I conclude that insofar as epistemology has turned to factivity, we need a U-turn back to an epistemology in which the non-factive aspects of cognition figure centrally. Some Basic Cases New Evil Demon (henceforth ‘NED’) cases and other cases of massive deception, such as brain-in-a-vat (henceforth ‘BIV’) cases, are innovations by philosophers. They are highly abstract thought experiments that can be useful in investigating the limits of our epistemic concepts or fringe areas of epistemic reality. However, assessing such thought experiments is a complex affair that requires both theoretical background and adequate specification.