Shadowhunters is ready for Mortal Instruments fans to dive right in.

'Shadowhunters' TV Show: This 'Ship Will Get Their Own Episode! New Title Revealed

Freeform's (former ABC Family) adaptation of Cassandra Clare's popular YA series won't follow the source material to the letter, but series star Katherine McNamara (Clary) promises that even the smallest details will have readers beaming with recognition.

"If you love the books, it's worth a watch, because we have lots of lines and scenes directly from the book," McNamara told ET Online. "We have Easter Egg props hidden all over that -- if you know the books -- things will make sense to you."

'Shadowhunters' TV Show: Will The Sizzy & Malec 'Ships Enter The Fast Lane? 'Love Triangles' Multiply At Lightning Speed

If you haven't cracked the cover of City of Bones, don't worry. Everything from steles to runes will be explained along the way.

And just because Shadowhunters is keeping true to the storyline, no amount of turned pages will ruin the fun. There will be surprises for everyone from hardcore fans to the casual reader.

"From point A to point B, we pretty much do the same thing," McNamara teased. "But the way in which we get there, we changed a few things, because we want to make it exciting for people who know the books cover to cover, and people who are new to the world."

Find out more when Shadowhunters premiers on Jan. 12 at 9 p.m. ET.