Dark things can happen on a long, cold Icelandic night… Iðunn is in yet another doctor's office. She knows her constant fatigue is a sign that something's not right, but physicians dismiss her symptoms and blood tests don’t reveal any cause. When she talks to friends and family about it, the refrain is the same ― have you tried eating better? Exercising more? Establishing a nighttime routine? She tries to follow their advice, buying everything from vitamins to sleeping pills to a step-counting watch. Nothing helps. Until one night Iðunn falls asleep with the watch on, and wakes up to find she’s walked over 40,000 steps in the night . . . What is happening when she’s asleep? Why is she waking up with increasingly disturbing injuries? And why won’t anyone believe her? “ The Night Guest pulls us by our throats down Reykjavik midnight streets in an unraveling nightmare. This book moved, thrilled, and terrified me.”―CJ Leede, USA Today bestselling author of Maeve Fly “A truly gripping read you can devour in one sitting.”―The New York Times "From its opening pages, Hildur Knútsdóttir's eerie and elegant The Night Guest wraps its icy fingers around you and pulls you in. It's so atmospheric, so well-crafted, and so truly, deeply unsettling that by the end, you feel every bit as haunted as its sleepless heroine. If you're a horror fan―or just a fan of great writing in general―you need to have this one on your radar!"―Rachel Hawkins, New York Times bestselling author of The Wife Upstairs "A genuinely heart-pounding read."―Olivie Blake, New York Times bestselling author of The Atlas Six "You can speed through this book in a single spooky night and be satisfied with the chills it leaves behind.”―The Wall Street Journal “This is psychological horror at its finest.”―Publishers Weekly, STARRED review "I inhaled this book. Not since Sarah Gran's Come Closer has every sentence sliced at the reader's heart. This book will bleed you out before you're done."―Clay McLeod Chapman, author of Ghost Eaters " The Night Guest pulls us by our throats down Reykjavik midnight streets in an unraveling nightmare, so much grief and fear and all we may be capable of leaving their marks beneath our fingernails and behind our eyes. This book moved, thrilled, and terrified me. Atmospheric, witty, frightening, electrifying, I would walk those nightmare streets again and again with Knútsdóttir. I absolutely loved it."―CJ Leede, USA Today bestselling author of Maeve Fly "Like the flashes of a waking nightmare, Knútsdóttir’s artful spiral of terror will have fans of Ling Ma, Paula Hawkins, and other flawed female narrators demanding more."―Booklist "A beautifully written story: visceral, layered, and haunting. I loved every moment."―Sunyi Dean, bestselling author of The Book Eaters Hildur Knútsdóttir was born in Reykjavík, Iceland, in 1984. She has lived in Spain, Germany, and Taiwan and studied literature and creative writing at The University of Iceland. She writes fiction both for adults and teenagers, as well as short fiction, plays, and screenplays. Hildur is known for her evocative fantastical fiction and spine-chilling horror. The Night Guest is her first book translated into English. She lives in Reykjavík with her husband, their two daughters, and a puppy called Uggi. Mary Robinette Kowal is the author of the Hugo, Nebula, and Locus Award-winning alternate history novel, The Calculating Stars , the first book in the Lady Astronaut series. She is also the author of The Glamourist Histories series and Ghost Talkers and has received the Astounding Award for Best New Writer, four Hugo Awards, the Nebula, and Locus Awards. Her stories appear in Asimov’s , Uncanny , and several Year’s Best anthologies. Mary Robinette has also worked as a professional puppeteer, is a member of the Award-winning podcast Writing Excuses , and performs as a voice actor (SAG/AFTRA), recording fiction for authors including Seanan McGuire, Cory Doctorow, and Neal Stephenson. She lives in Tennessee with her husband Rob and over a dozen manual typewriters.