The study of how the brain regulates learned fear has been fundamental to understanding brain function and has served as a pre-clinical animal model for fear- and anxiety-related disorders in humans. The current model has exclusively focused on primary triggers for fear, that is, fear acquired through direct pairings between a cue and a fear-eliciting event. However, fear is also elicited by secondary triggers, that is, cues that were never directly paired with the aversive event. These secondary triggers gain fear-eliciting properties by virtue of their association with primary triggers. The talk will present data showing how fear memories propagate across the memory network allowing for the development of secondary fear triggers, how those memories are regulated by fear to the primary triggers at the behavioural and neural level, as well as how they are supported by circuits in the brain.