The critical importance of sleep in our lives is extremely relevant subject to respond. It is an essential psychological and physical need whose deprivation causes serious problems in human health. Sleep is as normal and as important in our lives as breathing is. Like so many mysteries surrounding human existence sleep is one such amazing and unique phenomenon which becomes intriguing due to the power of dreams attached with it. Mathew Walker, a professor of neuroscience and psychology at University of Berkeley has attempted to unlock the secrets attached with Sleep owing to his twenty years career in research on the given subject. Broadly structured on four parts this brilliant exposition of such a grand thesis attempts to crack the code of sleep through a span of sixteen chapters. The author starts with a biological and medical justification of this essential and an irresistible process in our lives. Unless we know the mysteries attached with the process in the deep recesses of mind it is hardly possible to give this subject due attention which it demands. Nevertheless, the prime focus of the author is to bring home to his readers the repercussions of sleep deprivation and its consequential impacts in our lives in immediate terms and in the long term. He is of the considered opinion that ‘this silent sleep loss epidemic is the greatest public health challenge we face in the twenty-first century’. Therefore in the Appendix of the book are separately attached a prescription of DOs and DON’Ts for a healthy sleep. How do we know and experience Sleep? Two universal indicators do the work as the author suggests: First ‘is the loss of external awareness’ and second is the ‘sense of time distortion’. Thalamus a small structure within the brain located just above the brain stem plays the role. The main function of the thalamus, thus, is to relay motor and sensory signals to the cerebral cortex. While sleeping thalamus blocks the signals. We may be smelling and hearing but not conscious of it. The ‘sensory door’ through which sensory signals pass is closed when we sleep and opened when we get awake as result of release of certain chemicals. The sleep pressure in our body is created by the accumulation of a chemical called ‘adenosine’. When we fall asleep the adenosine in the body starts clearing away till we wake up. Tea, Coffee and those products containing caffeine put a mask on the receptors of adenosine. The impact of this mask is 5 to 7 hours. Melatonin is another important chemical that sends sleep signals to the brain. Blue light stops pineal gland in secreting melatonin. Hence those having sleeping problems are advised to stop getting exposed to blue light at least two hours before sleep. The author classifies sleep in four stages. It is an important aspect to understand the process of sleep. 1. Transitional 2. NREM Light Sleep 3. NREM Deep Sleep 4. REM Dream Sleep. The transitional sleep is the beginning part of sleep when we hit the bed and our body and brain prepare to go to sleep. Our body temperature, blood pressure, and heartbeat start going down. During this period if someone awakes us, we feel that we were not sleeping. Duration of this stage is a few minutes. The second stage that starts after the transitional sleep is the NREM ( Non Rapid Eye Movement). Eyes don’t move in this stage of sleep. During this stage of sleep eyes don’t move. Our heart rate slows down, blood pressure and body temperature too falls down. This stage of sleep is also called light sleep and comprises about 45% of the total sleep duration. It is an important process as new things acquired throughout the day are stored in ‘hippocampus’ part of the brain. Memory and maturation process of those people gets badly affected who don’t enjoy this part of sleep. Those students who struggle to remain awake by using energy drink rather face memory loss. In the NREM lies the third stage of sleep—the deep sleep. A person enters this stage in approximately 45 minutes of falling asleep. Blood pressure, heart beat and body temperature is lowest during this stage. Deep sleep is virtually a deep dip into the inner recesses of mind. A person in deep sleep can’t be awakened so easily by noise or disturbances around. In case a person wakes up during this stage of sleep he is likely to feel disorientation. This deep sleep is crucial for the health of brain and body. It cleans all the toxic materials particularly it detoxifies the liver, increases immunity and so many diseases inside the body are washed away. It is for this reason that after enjoying this part of sleep every person feels freshness inside his body and mind. Failure to enjoy this stage of sleep also keeps the waste products inside the brain sticked with the prefrontal part of the brain which makes the decision inside the brain. Those suffering from Alzheimer or dementia are mainly deep sleep deprived in their lives. The fourth stage is REM (Rapid Eye Movement). It is also called dream sleep. Like previous cycle it also takes 90 minutes by average. Whereas deep sleep dominates the first half the dream sleep takes over the other half. Both stages of sleep are crucial for our mental and physical health. In this stage we dream and our blood pressure and heart rate increases. Since we are experiencing a great activity inside our brains therefore our muscular system is paralyzed by the brain. Those deprived of dream sleep are deprived of rationality, good memory, creativity are interested in drugs intake. Evaluation of the personality of teenaged student can be easily made through gauging the quantum of both deep and dream sleep he/she is having or vice versa. Ironically this significant aspect is commonly ignored by the academia and various other reasons are attributed to deviant behavior amongst students/youngsters. It is high time to realize the productivity of sleep in our person and social well being. Stress, over work and burden rather decreases output. Since man shifted to sleep on ground from sleeping at tree, the quality REM sleep improved and brought great magnitude of creativity, rapid evolutionary rise to power and emotional intelligence. There is indeed no substitute for hard work but unfair and consistent subjugation of human mind in competitive working environment has altogether changed the human society now, the author laments this situation. He tosses up the other side of the coin. Talking in economic terms, the author claims that due to improper sleep, US economy loses $ 411 billion each year. To strengthen his argument he quotes Dr. Christopher Barns, a researcher in the Foster School of Business that ‘under-slept employees tend to become unethical. Mathew Walker also draws attention to another imporant aspect. Humans are not experiencing sleep as nature intended. Our sleep is essentially in a biphasic pattern whereas we are having it in monophasic way. We sleep only once at night whereas all the pre-industrial cultures have a two phase sleep culture. Sleep at night and an approximately 90 mins nap at afternoon. Modenity has unfortunately deprived us of what even pre-seventeenth century Western European used to enjoy. The writer is superintendent of Police and currently serving as District Officer Frontier Constabulary, Hayyatabad Peshawar