In contrast to the accepted wisdom that memories become fixed over time, recent evidence has renewed interest in the dynamic quality of memory, suggesting that even old memories are subject to revision and reconsolidation given the right circumstances. We discuss a new paradigm developed to study reconsolidation of episodic memory in humans, showing that reminders can open a previously established memory to updating based on new experience. We show that under laboratory conditions the experimental context plays a critical role in determining whether or not such memory updating will occur; but that under conditions where the context is highly familiar other factors might play this role. The nature of context is explored, linking our results to work on hippocampus, and the results of a neuroimaging study exploring the impact of reactivation of well-established memory are described. Our results, situated within a broader context, set the stage for future explorations of the cognitive neuroscience of the malleability of memory.