Sometimes building suspense for the reader means making sure they know what they’re supposed to have suspense about.
This can mean some level of over-explaining. There’s so much in the writer’s head that never makes it to the page, but there’s also a lot that’s implicitly obvious to us that we don’t realize isn’t clear to a reader (this is one good reason to have a beta reader at the very least look over your work before submitting it to an audience).
One thing I’ll sometimes do is explain as much as I can about what the rules of the story are upfront (particularly in stories that have a lot of secondary world building), and allow the characters to question the mystery that I want the reader to wonder about. Some writers are a bit more cagey and subtle than I am, maybe it’s an ADHD/spectrum thing where I’m over explaining (like right now, lol) because I’m afraid of not being understood.
But personally, I’ve never really seen an audience get mad because they fully grasped what was going on and the rules of how the story is going to work. They might get bored or exasperated, but in general people don’t mind the story recap at the beginning of a tv episode, they don’t mind the reminder of how stuff works, or what’s going on. But they don’t like being confused.
One way as a writer that you can make sure that the reader/audience knows what to focus on is literally pointing them to it. “Here’s all the circumstances around the murder, given in extreme detail. What we don’t know, and what the characters are also wondering, is the identity of the murderer.” Having the murderer’s identity and some lingering questions about why exactly everyone cares about this murder, or why this particular detective is in town solving it, may already be too many mysteries depending on the length and complexity of the story. Your audience especially shouldn’t be wondering about extraneous mysteries if you don’t intend them to be wondering about those things. That’s another reason to get a second pair of eyes on complex stories.
Mysteries provide an element of cognitive engagement for your reader, which is one way to get them hooked on your story. (The first three books of the Harry Potter series in particular were in fact mysteries, one reason for their enduring popularity IMO.) Readers like to be cognitively engaged and asking questions. But they don’t want to feel dumb because they don’t have all the relevant facts, because you haven’t provided them or you pulled a fast one on them. In general, they want to be there with the character in terms of knowledge level, maybe even more informed than the character if you don’t want your story to feel claustrophobic.
For example, if it’s a “who done it?” don’t have the murderer not even show up in the story until they get pulled out of nowhere, it pisses everyone off and it makes them feel cheated. Don’t pull a surprise twist that has no lead up, or have scenes floating around with no connection to other scenes because it would be “a cool reveal” (*coughWestworldcough*). This also helps keep your reader from wondering if stuff is there on purpose or not. I’ve seen readers forgive a lot of writerly sins, but the only one I’ve never seen them forgive is the writer not knowing their own story and all its details better than the reader does.
Give your readers all the tools you can, and don’t be afraid to give them obvious signposts to what you want them worrying about, so that they stay focused and engaged with the narrative and you can guide them through a satisfying experience.






