Optimality is a key organizing principle of science, but the patterns of connections within real-world networks do not always respect it.

A small molecule forces the protein-translation machinery to overlook the signals that would otherwise result in its premature termination. Genuine stop signs are, however, read and obeyed.

What are neural networks doing when the brain is at rest? It turns out that in primates, even under conditions of deep anaesthesia, some of these networks undergo highly organized patterns of activity.