In most cases, truth is stranger than fiction. But sometimes we need strange fiction to show us the truth. My favorite works of science fiction and fantasy take place in a world that largely resembles our own, and shine a spotlight on the issues of today by blending fantastical imagination with real-world commentary.

Take “Buffy the Vampire Slayer.” High school is hell (literally). Coming out (as a Slayer) is hard. The man you love could transform after sex into someone you no longer recognize (say, a vampire). Allusions to the speculative are common in everyday speech: The untested drug is a “magic pill,” the horrible boss is the “devil himself,” or the female politician is “possessed by a Jezebel spirit.” Taking these propositions seriously can shine a light on what ails us (corporate greed, worker exploitation, good old-fashioned misogyny — take your pick). It’s also what inspired me to play with the idea of actual monsters haunting an abortion clinic in my latest novel, “We Dance Upon Demons,” after I was called a “demon” while volunteering at Planned Parenthood.

When used well, speculative elements take a familiar concept that our brains might otherwise gloss over as familiar and make it just different and exciting enough that we can see new or deeper dimensions. In contemporary stories, they create a gateway for the reader to put herself in a character’s shoes. It’s hard to imagine, for example, how I would fare in the Hunger Games (poorly, I’m sure), but I definitely know what I would do if I started seeing demons at work (Google symptoms of a brain tumor).

Here are some of my favorite books that make a contemporary feast out of the simple question: What if?