Adaptation is an imprecise art.

Netflix's Locke and Key really is the perfect storm of an adaptation, with a passionate, dedicated fanbase, a volatile mix of horror, fantasy, and drama genres, and a cogent beginning, middle, and end to the story that's already written and set in stone--unlike some other recent high profile adaptations.

But even near-perfect source material can't be adapted word-for-word (or in this case, panel-by-panel) to a completely different medium. Most fans understand this, and the changes Locke and Key has experienced on its journey from comic book pages to streaming on Netflix are more a source of fascination than frustration.

As fans of the Locke and Key comics ourselves, we couldn't help but jot down all the big changes we noted as we watched the series. We listed them below for your pleasure.

Here's your spoiler warning: We'll discuss events from throughout the show and the comics below. You've been warned.

We also wrote down as many Easter eggs and references as we could spot throughout the season--there were so many, we had to break it into three separate articles (here's Episode 1, Episodes 2-5, and Episodes 6-10). If you want to know more about the comics, check out every key from the books (and our explanations of what they all do).

And for some Locke and Key news, check out the fact that work on Season 2 has already begun, not to mention Joe Hill's recent announcement of a new Locke and Key one-shot issue called Locke and Key: Pale Battalions.

1. Horror/fantasy balance

The Locke and Key comics strike a remarkable balance between the magical fantasy of Keyhouse as discovered by teenagers and kids, and the horror of the murderous, otherworldly forces who want the keys for themselves. But while the comics lean more toward horror, with ample body horror and gore throughout the series, the show is much more concerned with the fantasy. It's a major tonal shift that might seem jarring to fans of the comics, but it was no accident: Speaking to GameSpot, executive producer Carlton Cuse said he and Locke and Key's other adapters tried to strike a ratio of "three cups fantasy to one cup horror."

"It's sort of an intuitive process," Cuse continued. "[Showrunner] Meredith [Averill], we worked on Haunting of Hill House, and I had done Bates Motel before this, and I think that for both of us, we loved the kind of inviting, warm, heartfelt undertones to Joe [Hill]'s comic. And we wanted to have that be reflected in the story, in our adaptation of it. And I think that we felt like horror was an element, but we were much more interested in structuring the show on the fantasy axis."

2. Mark Cho's fate

The show's opening is very different from the original version in the comics. The first character we meet is Mark Cho, who, in the books, didn't survive into adulthood. Granted, he still has practically no bearing on the story, since he immediately self-immolates moments after we meet him in the show.

3. Matchstick Key

Speaking of which, the Matchstick Key is brand new for the show. There are dozens of keys in the comics, but author Joe Hill never wrote one that creates fire.

4. The Savini Squad

Some of the show's characters, like Tyler, Bode, and Kinsey, are more or less the same as their comics counterparts (or close enough, at least). But others have been completely reinvented--like the Savini Squad. In the books, Kinsey's friends include Scot, Jamal (not in the show), and Jackie (reinvented to be Tyler's love interested in the show). They don't have a name for themselves, they don't care about horror movies, and they're not making a movie. Scot is completely different in the books, with a more punk vibe, including massive tattoos and a less shy demeanor. The other Squad members, including Gabe, don't exist at all in the comics.

5. Other side characters

As we already mentioned, Jackie (above) is very different in the books--instead of being Tyler's love interest and an avid enthusiast of Jane Austen and extracurricular activities, she's on the track team with Kinsey and eventually starts dating Scot. Several other side characters, like Eden and Javi, were invented wholesale for the show, while some book characters, like Jordan Gates, don't exist in the show.

6. Sam Lesser

Sam is significantly different in the show. He's much less threatening, and not just because the show skipped the scene where Tyler bashed his face to bits with a brick. Show Sam has a much smaller scar on his forehead, rather than criss-cross stitches from having his face reconstructed. In addition, the books never portray Sam as a weird sort of class clown, like the show does. He's much more sinister--when he attacks the Lockes the first time and kills Rendell, he has a friend with him, and the attack also involves assaulting Nina (granted, something we're fine they left out of the show). But overall, book Sam is far more threatening--he even leaves a trail of brutally murdered people behind when he breaks out and travels to Keyhouse.

7. Dodge's rules

The show has an odd conceit that wasn't present in the comics: Dodge is unable to take the keys from the Lockes--the keys have to be given to her. This probably has something to do with the fact that the Lockes are the "Keepers of the Keys" and are tied to them by family magic, though it isn't fully explained in this season. In the books, Tyler and Kinsey simply hide the keys really well.

8. Nina's alcoholism

Nina is a drunk in both the show and the books, with one key difference: Her comics storyline doesn't involve her falling off the wagon, since she's already drinking heavily when the story begins. Her alcoholism gets worse throughout the comics, but she's not in a 12-step program like she is in the show.

9. Identity Key

The Identity Key is another invention for the show, and it makes a ton of sense. The comics featured two separate keys for changing your appearance: the Gender Key, which changed your gender, and the Skin Key, which altered your race. The Identity Key is a much more versatile--and progressive--alternative for those two.

10. Head Key

The Head Key is another example of something that works very differently in the show than it did in the comics. The panels of various characters opening the tops of their skulls like toy chests and peering down at what was inside are some of the most famous scenes in the books, but for the show, the filmmakers decided to make the key's use slightly less horrifying. Instead of causing the user's head to open like a tin can, it spawns a door or other entrance (such as an actual toy chest) nearby in the room.

11. Mirror Key

Another new key invented for the show is the Mirror Key, which Dodge explains to Bode is a way to trap enemies in a "prison of the self." When used with a mirror, it causes a reflection of the user to appear and beckon them into the mirror. Nothing like this key exists in the books, though there are plenty there that are even stranger.

12. Flower Key

There's one more brand new key in the show, and in a way, it's the most mysterious one: the Flower Key (at least, that's what we're calling it). Its exact function is hard to describe--Tyler and Kinsey turn it in a tree, which causes jars containing their uncle Duncan's memories to rise from the ground. Rendell Locke likely used the Flower Key to hide them there, but is that its entire purpose? It seems like a really specific thing.

13. The ghost of Grandpa Chamberlin

Chamberlin Locke is a character in the comics, but not in nearly the same way. Bode never encounters him while flying around using the Ghost Key--that scene is completely made up for the show. Instead, Chamberlin is a figure in Keyhouse's past who's seen in flashbacks and one-shot issues.

14. Kinsey's Fear

Kinsey does the same thing in the comics and the show: She takes the fear out of her head. In the comics, where the Head Key works differently, Kinsey's fear is about the size of a mouse, and she keeps it (along with her sadness) trapped in a soda bottle in her nightstand. In the show, her Fear is a human-sized personification that she buries in the woods.

15. The Music Box

The Music Box and its accompanying Key play a much smaller role in the books, where the Lockes discover it later on and barely use it. They certainly don't bring it to school and use its power to humiliate a classmate.

16. The Shadows

In the comics, the shadows take very specific shapes, depending who cast them in the first place. In the show, they're mainly all the same shadowy monster.

17. Behind the Black Door

When the Black Door is opened in the comics, the other side is a Lovecraftian hellscape filled with viscous, eyeball-shaped demons who reach through and inspire unrestrained slaughter in whoever they touch. In the show, it's a lot more tame. Who's afraid of "glowing bullets"?

18. Dodge/Lucas/Zack/(Gabe)

This may be the largest difference between the books and the show, and it's an extremely effective one. In the books, when Dodge escapes the well house, she immediately uses the Gender Key to turn back into her "natural" form: that of Rendell's best friend, Lucas. Lucas cuts his hair, gets a weird lip ring, and immediately attaches himself to Tyler and Kinsey. Going by the name Zack, he becomes the former's best friend and dates the latter, all to manipulate them into confiding in him about the Keys. Bode doesn't recognize him from the well, but several other people do--since he looks exactly like Lucas--and he has to do a whole lot of murdering to keep his cover. But while we, the readers, know who he is, it takes the Lockes a long time to catch on.

In contrast, the character "Zack" doesn't exist in the show at all. Dodge attempts to seduce Tyler, but makes a stupid mistake and breaks her cover. She manipulates Bode openly--not that there's much the kid can do to fight her. She lives at Ellie's house as Lucas, but Ellie and Rufus keep that a secret. And comics readers watching the show for the first time will likely assume they skipped the Zack storyline entirely--until the final moments of the Season 1 finale, when it's revealed that Gabe played the same role all along, manipulating Kinsey with the help of the Identity Key. It's really an ingenious twist.

19. Missing Keys

The show's story doesn't totally align with the books, but in general, at this point in the source material, the Lockes had discovered several other keys. For example, the Hercules Key made the user three times stronger than normal, while the Giant Key made them huge (as seen above). Those keys have yet to be introduced in the show, but they may just be saving them for later seasons.