Hibernation is one of nature's greatest mysteries. How do animals manage it? For half the year, indeed half their lives, they lie cold and lifeless in a burrow without suffering any harm. If we humans lie flat for just three weeks with a cast, our leg muscles become thin and weak. On her journey into the hidden world of hibernators, biologist and researcher Lisa Warnecke tells the story of four animals she has accompanied through hibernation under often adventurous conditions across four different continents: a hedgehog in the midst of a German metropolis, a lemur in tropical Madagascar, a bat in the icy wilderness of the Canadian prairie, and a small marsupial in sunny Australia. Her book dispels widespread misconceptions.