Novels are a type of book that contain one longish, fictional-ish story. Novels may or may not contain characters, who may or may not be people or other animals.
You will generally encounter novels in a printed form. You can find them in libraries, bookstores, houses, and sometimes on the street. Because they are larger than short stories or pamphlets, they might be somewhat heavier, and pose a slight danger if they fall on you or if someone hits you with one. Increasingly, though, novels are available on the internet, and can be read on a phone, computer, or tablet.
Because novels are a compelling medium for investigating ideas, they might put a reader in close proximity to ideas that they haven't thought about before. Some of these ideas might be bad or challenging. There is some danger that the reader might adopt a bad idea or have one of their long-held ideas changed, which can occasionally be stressful.
Additionally, people who read novels are often tempted to write their own novels. This process is time-consuming and only a small fraction of novels are ever finished. Even fewer still are ever read. Therefore, novels sometimes threaten to waste readers' time with fruitless pursuits. Personally, we advise readers who are interested in writing a novel to try anyway. Those who do should know ahead of time that their novel will quite likely be bad.
As a final note, novels are usually preoccupied with a specific topic or set of topics, which can lead to an unhealthy amount of interest in that topic on the part of captivated readers. For instance, if you read Moby-Dick, you may become unfortunately obsessed with the illegal and highly dangerous practice of whaling, which you more or less can't even do anymore.
All in all, novels are only a little dangerous.
