A small nucleus in the brainstem called locus coeruleus (literally the ‘blue spot,’) is the primary source of a major neuromodulator, norepinephrine (NE), an important mediator of the ‘fight or flight’ response in animals. However, very little is known about the local connections of this small albeit critically important group of neurons. A recent pioneering study now reveals the cellular composition and circuit organization of the locus coeruleus in adult mice.