Here’s a brain teaser for you: in the far-flung future, a human detective teams up withan android to solve a homicide. Is this a mystery novel, or is it science fiction? The great thing about Isaac Asimov’s The Caves of Steel (1954) is, no matter how many times you read it, and no matter how many angles you look at it from, it’s very difficult to assign it definitively to either genre.
Same goes for Richard Morgan’s Altered Carbon (2002), which is also set in the future, although Morgan doesn’t fling it quite as far as Asimov did. The book’s got all the trappings of SF—marvelous new technologies, new societies, and so forth—but at its heart it’s a noir. A man is hired to solve a murder, gets mixed up with the victim’s seductive wife, and risks his own life in some of the darkest, seediest corners of the city. Is the book SF or is it a mystery?
Tell you what: Why don’t you check out this list of SF mysteries and let me know which genre you’d put them in, if you had to choose only one. And let me know which titles you’d add to the list, too.