Suspenseful, Mysterious, and Complicated
Thomas Small seems to think he's living inside a scary movie, and he kind of is, but not the way he thinks. Luckily, he's never in any real danger. But, since the story is mostly from his point of view, every single thing that happens seems like a warning of danger, or the frightful moaning of supernatural, even demonic forces. We can't blame him; the events in the story really are scary, mysterious, and complicated. Thomas's point of view plays this up more than, say, Mr. Small's point of view would have. Here's an example of a complicated, mysterious moment that builds suspense, makes us want to know what's going on. This is from when Thomas is under the house on the first day of the story:
Thomas felt frantically along the wall. The wall was wood. […] Thomas pounded on it, hurting himself more, causing his head to spin. He kept on, because he knew he was about to be taken from behind by something ghostly and cold. (4.5)
The whole story is kind of like this – we feel our way through its dark and winding caverns, wondering if we'll see ghosts, or like here, find ourselves in a hidden passageway that opens onto something warm and friendly, like the Small's kitchen. That's what happens next. When Thomas begins to scream in fright, his mother slides the wall open. No ghosts (yet!) – but rather, a hiding place for people running from slavery. Even at the end of the story, when all is revealed, much mystery remains. For one thing we don't know for sure whether the ghost of murdered Dies Drear and the murdered slaves lurk about the place or not.