Walker films Bialik's late-night anxiety loop in real time — the scrolling, the overthinking, the 3am ceiling stare. A neuroscientist diagnosing a fellow neuroscientist creates the most intellectually charged episode of the series.

Davidson has never been this candid on camera — or this vulnerable. Walker films the exact moment sleep refuses to come, then breaks down the neuroscience of BPD, trauma and the fight-or-flight bedtime trap in terms Davidson has never heard before.

Decades of breaking news, war zones and election nights have left Cooper with a staggering sleep debt. Walker runs live calculations on camera — showing Cooper exactly what those decisions have cost his brain — and how to start repaying it.

Richie's schedule is genuinely nocturnal — creative work at midnight, social events at 2am, children at 7am. Walker maps her circadian biology on camera and shows her, for the first time, exactly how out of alignment her internal clock has become.

The most powerful episode of the series. Tyson has spoken publicly about nightmares for years. Walker stays through the night — listening without judgment, then deploying Imagery Rehearsal Therapy on camera in a moment of genuine, unscripted television.

Lyonne's bedroom is a crime scene of bad sleep hygiene — screens, irregular hours, caffeine at midnight, chaos. Walker films a forensic audit of every choice, explains each one's biological cost, and rebuilds her sleep environment from scratch.