A Night of Sleep, Traced

Tracing a night means following one sleeper from circadian signal to final waking, naming every stage, hormone, and disruption in order.

One full night worked through end to end — the evening melatonin rise, the first descent into N3, the growth-hormone window, the lengthening REM periods after three in the morning, a single apnea arousal at four that never reaches awareness, the shift in stage proportions before waking, and the difference this makes to what was consolidated. Ends by locating exactly where in the night one lost hour is taken from.