So I'll focus Locke & Key on the story, since I can't really speak to the art, which I realize is typically a BIG part of graphic novels. Except, of course, I don't want to throw out too many spoilers so let's see what I can manage.
Locke & Key starts with the murder of Rendell, patriarch of the Locke family. Nina and her three kids, Tyler, Kinsey, and Bode move to Lovecraft, MA to Keyhouse, a home that's been in the Locke family for years, in an attempt to put these terrible things behind them. Tyler's depressed, Kinsey doesn't fit in, Nina's started drinking and Bode finds a strange key that seems to let him leave his body.
The kids slowly unlock (ha) the mysteries of Keyhouse and continue to find keys that allow them to do any number of crazy, magical things. The Ghost Key lets you leave your body and float around like a ghost. The Head Key lets you open up your or someone else's head and either put information in or take memories out. There are a ton of keys and it's fun to learn what each one does.
Joe Hill is a horror writer and this falls into that genre, though with a lot of fantasy elements. But the story can and does get pretty violent. It also gets sad at times. I finished up the book while riding on an exercise bike and I think I went the fastest I've even done trying to outrun the feels.
I highly recommend listening to this as an audiobook. Like I said in an earlier post, it's like a radio play with a number of different actors portraying all of the characters and various sound effects used to keep you in the story. Everyone was distinct enough that I never missed speaker tags that are part of a more traditional audiobook. And I liked the story enough I'm thinking of picking up the actual graphic novel, though as a set, if that's an option, please & thank you.
(P.S., don't you love my seasonally appropriate reviews. I'm so good at this...)
Hill, Joe. Locke & Key. Audible recording