You finish your shift exhausted, but your body won't let you sleep. The world is awake, light floods through curtains, your circadian rhythm fights every attempt at rest. Night shift doesn't just steal sleep-it fundamentally disrupts the biological systems that make sleep possible in the first place. This book explores what working against your natural sleep-wake cycle actually does to your body and brain. It examines how circadian misalignment affects hormone regulation, immune function, and mental health, why "just sleep during the day" fails when your biology is programmed for nighttime rest, and how chronic sleep debt from shift work compounds in ways office workers never experience. It reframes night shift fatigue not as poor sleep habits, but as biological warfare between work schedule and evolutionary design. Rather than offering standard sleep tips that assume daytime sleep works the same as nighttime rest, this book helps shift workers understand the unique challenges of sleeping against circadian rhythm. It explores light exposure management, strategic napping, nervous system recovery between shifts, and what it means to protect sleep when your schedule undermines every natural sleep signal. It's about working with severe biological constraints, not pretending they don't exist. For night shift workers exhausted by advice that doesn't account for circadian reality, this book offers validation of the struggle-and practical understanding of what actually helps when your body and schedule are in constant conflict.