[A] masterwork of speculative fiction ... I Am Behind You is pre-eminently readable. The pacing and structure kept me turning the pages. And while I was intrigued by the premise, it was the sheer weirdness of the book, its insistence on subverting expectations at every turn, that made it so good. I Am Behind You is my favorite kind of novel — utterly unclassifiable. It resists genre. While it might be called horror, it is also a suspense novel, a fantasy novel and a character-driven exploration of the state of humanity in our time ... Lindqvist has defined his own style and genre. It’s not horror. It’s Lindqvist.
An exercise recalling Stephen King’s Under the Dome ... the explicitly supernatural elements—lurking monsters having something to do with past traumas—never satisfyingly coalesce, but when Lindqvist channels the classic Twilight Zone episode The Monsters Are Due on Maple Street, showing how quickly humans will turn on one another, the results are chilling.
[An] ambitious and frustrating novel of cosmic horror ... The characters, the group dynamics, and the unfolding mystery of what’s going on and why are well-depicted and engrossing, but the ending peters out in a futile attempt to remain emotionally satisfying while still leaving most events unexplained. A future book may shed more light, but the first installment makes it difficult to maintain enough investment in the story to want more of it.