Glasslands - Spartan Mental Processing

Naomi shoved past Vaz and followed the noise. BB felt her heart rate fall to 140 as her adrenaline steadied, and she moved forward with her rifle trained—much more deliberate, thinking more consciously. The next thing she saw spiked her heart rate for a couple of seconds and she’d already opened fire on it before her frontal lobes identified it as a Brute.

“Four down,” she said. “Two left.”

- Halo: Glasslands, Chapter 10