It's easy to argue that horror, whether on screen or on the page, relies more on careful pacing decisions than other genres. Should the most disturbing elements jump out at us from the opening pages? Or does a slow build work better, lulling us into comfort before erupting with the shocking or the unexplained? Nicholas Russell's debut novel Observer (Ecco Books; 336 pages) opts for the latter approach, building slowly, grabbing on and luring us in until it's too late to turn back.

The prose moves between Renata's narrative as she searches McNairy for clues and journal entries from Corinne, her co-worker Percy, and Francis Brown, a surveyor writing in 1905 whom Percy considered the source of answers for McNairy's unexplained eccentricities. The journals don't appear in sequential order, as Renata sometimes picks up sections and reads them at random. At a particularly important moment, she doesn't read the entry provided to the reader, creating dramatic irony that plays into a specific, rather enjoyable genre trope. At times, it can feel disorienting, as the journal entries don't always make it immediately clear who the writer is. Still, that disorientation feels deliberate, keeping the reader on their toes and creating a sense of eeriness.

The mystery of whether Corinne is alive is established in the opening pages and drives the narrative. But the novel takes time to settle in as we slowly realize that one mystery becomes several layered plots. Renata must figure out if her mother is alive, but she also has to determine what happened to her if she's dead, and what is causing the general creepiness in the town of McNairy. Initially, progress seems like it’s working in reverse, as Renata notes after her experiences in the town: "Renata remembered why she had come to McNairy in the first place. She didn't know her mother at all." Information leaks out in bits and pieces, and the townspeople won't offer Renata or the reader full explanations. It feels like Russell is deliberately toying with the pace, taking time to work out different narrative components and choosing when to release information to build toward a bigger payoff. He leaves us wondering what exactly the novel is.

We eventually get the answer: Observer is a horror novel. The uneasiness and oddities of McNairy slowly morph as Renata climbs the mountain to the observatory, while other information emerges from the journals. Rather than announcing its intentions from the beginning, Observer waits until we're invested in complex mysteries, then lets supernatural elements ooze in, bucking clichés and making its reveals unpredictable. Russell also doesn't lean too heavily into the basic tropes we might expect. One exception is tied to the dramatic irony: there are moments when we beg Renata to do one thing, but she insists on doing another, as though we're watching her run back inside the house toward the killer.

The delayed onset of the horror element, and the way the journals jump between different points of view, create a puzzle we want to piece together. How quickly we do depends largely on how we interpret clues from the journals and what we infer Renata experiences in key moments in McNairy. The novel asks a lot of the reader as it builds to its tense, strange conclusion, with the overall weirdness developing slowly. It's worth giving each journal entry a close read to get the full picture of what might await Renata, even before she experiences it.

Russell's prose is descriptive, and it often employs longer sentences to build tension, particularly in the novel's climax. The prose avoids the halting style and short sentences we often encounter in similar moments in fiction. It excels at setting the scene and letting the reader bask in the world. At times, particularly in Francis Brown's journal, the prose also mixes in both natural and supernatural elements, offering subtle hints on what we can expect later: "I heard the woman’s voice all morning, a low, stuttering tone that echoed from far off places," Brown writes in one entry, then continues in the same paragraph, "I walked back to my quarters when a raven flew within inches of my head and from its beak the woman’s voice spoke. 'Do this in my memory. Do this in my memory.'" Overall, the prose is a considerable strength, particularly for readers who prefer more figurative language.

The novel clearly wants to heighten the weirdness and not leave the the reader with cut-and-dried answers. It's open to interpretation, particularly the motivations of individual characters. One example of this ambiguity can be seen in Ken, a post office clerk, who initially seems like a helpful source of information for Renata. But their final encounter takes an unexpected and disturbing turn. McNairy's characters often resist easy categorization, and their motives are rarely spelled out. This leaves us to question their trustworthiness and intentions throughout the story. The lack of clear answers can be intriguing, drawing readers deeper into the novel's atmosphere of uncertainty and inviting them to judge whom and what to trust. At times, that leads to curious choices that don't quite land, which can add to the sense of disorientation. If the goal was to knock us from our bearings and swerve when we think we know what happens next, it can work, as many unpredictable moments do. However, the constant ambiguity requires the reader to engage actively with each character's choices and perspectives, and not everyone will meet the novel's demand for patience and interpretation.

Observer is a deliberately mystifying novel that ultimately succeeds in its central aim: leaving readers feeling unease rather than satisfied with a tidy ending. Its gradual accumulation of dread brings to mind the works of Shirley Jackson, particularly The Haunting of Hill House, and should appeal to horror fans who prefer a slow build. It doesn't answer all its questions, nor does it try to, but it serves its genre well, building to a visceral, unexpected ending that will appeal to fans of the genre and those looking to wade in.