✓ The brain tends to be immune to inflammation and abscess formation, despite chronically and recurrently infected neighboring structures, and not uncommon pyemias and septicemias. Experimental inoculation of the brain tissue with microbes confirms this clinical experience. When brain–microbial interaction overcomes immunity, reactivity sets in, resulting in inflammation and abscess formation. Brain abscesses tend to stand apart from the host tissue so as to allow easy aspiration and/or ablation. A brain abscess is a dire neurosurgical emergency. The saving grace is that a few quick steps yield excellent results.