Alchemy.
I've been noticing that alchemy has been popping up in a lot of YA titles lately. The following is not, of course, meant to be remotely exhaustive—these are just the ones that came to mind:
Bloodlines & The Golden Lily, by Richelle Mead: Our heroine is Sydney Sage, alchemist (it also turns out that she has magical powers)! In this series, alchemists are, like, a secret society that polices vampires and keeps them hidden from the human race. Even though they hate them. Or... something like that. It makes more sense in the books, I promise. It's a spin-off of the Vampire Academy books—Sydney first appeared in Blood Promise.
The Alchemy of Forever, by Avery Williams: In this one, the local alchemist's son made our heroine immortal—well, kind of—way back in 1349. Since then, in order to, you know, keep living, she's forced to steal bodies whenever the one she's currently inhabiting starts to break down... which is every decade or so. Now, though, she's had enough with the killing and the abusive alchemist's son. So she plans to escape and commit suicide... but not everything goes as planned.
The Other Countess, by Eve Edwards: Our heroine's father is an alchemist! Who spent all of her true love's family's money! So that's a problem.
This Dark Endeavor: The Apprenticeship of Victor Frankenstein #1, by Kenneth Oppel: On his way over to the Dark Side, Anakin Skywalker Victor Frankenstein discovers a secret Dark Library full of dangerous alchemical texts. Later, he and his crew seek out the help of alchemist Julius Polidori in their attempt to create the Elixir of Life. It... doesn't go well.
The Iron Witch & The Wood Queen, by Karen Mahoney: Like Sydney in Bloodlines, our heroine Donna Underwood was born into a secret society of alchemists. There's a war going on between the fey and the alchemists, and poor old Donna is stuck right in the middle of it... while she attempts to navigate high school and all that jazz. I haven't read the second one yet. I should probably get on that.
The Strange Case of Dr. Jekyll and Mademoiselle Odile, by James Reese: Although the word alchemy is never technically used—and it's certainly a toss-up whether what they do is chemistry or magic—the focus on Odile and Dr. Jekyll's mysterious scientific process is so central to the story that it's worth including on the list.
The Book of Blood and Shadows, by Robin Wasserman: An alchemical machine that can talk to God! Did it ever exist? Does it still exist? And if so, should it? AWESOMESAUCE WITH AN EXTRA SIDE OF AWESOME.
Anyway, those are the titles I came up with. Any suggestions?