The Sleepwalker by Lars Kepler

The Sleepwalker is the brand new 2025 Detective Joona Linna crime thriller by Lars Kepler, the pseudonym of the acclaimed husband and wife author team Alexandra Coelho Ahndoril and Alexander Ahndoril. The novel opens with an alarming burglary call at a winter-closed campsite near Stockholm where police discover a brutal scene: a man killed with an axe and dismembered, blood covering the area, and a seventeen-year-old young man found asleep using a severed arm as a pillow. This boy, Hugo Sand, is the son of a famous writer and suffers from a rare form of somnambulism triggered by nightmares, making him either a witness or perpetrator, though he recalls nothing. Detective Joona Linna involves Erik Maria Bark, an old friend, to use hypnosis to uncover what really happened. This investigation ignites a complex pursuit of a serial killer entering a highly active phase. The book is a 512-page trade paperback published on July 29, 2025. Lars Kepler’s Joona Linna series has sold 15 million copies in 40 languages, with this installment continuing the high-stakes, gripping crime thriller legacy.