Library Puzzle

Hello, I’m a DM and wanted to get some ideas for a puzzle. The party is about to enter into a small library and they need to find three specific books for information moving forward. I don’t want it to just be a bunch of investigation checks. The setting is the Raven Queen’s Fortress of Memories to give an idea of the theme. Any help is appreciated, thanks!

Make numerous clues.

Pick 3 books that you think would be relevant, and make it obvious that they need 3 - three lecterns, for example - so that they understand the assignment - put 3 books on the lecterns.

Then, make a small library worth of books. You can streamline this by adding some series, such as "Family Lines of Faerun volumes 1 to 438", to make it feel like an aristocratic library.

Then, on the side of the door that the party can access, have clues. Make at least 3 clues per book. Give them several rooms to explore which exist only to house the clues.

Given the Raven Queen's presence, and assuming that my knowledge of her is still relevant, she's the goddess of Fate, Winter, and Death (or The Dead). Thus the three books they will need can be related to Fate, Winter, and Death.

This is where I would then lean toward the Addams Family Library:

Add effects when the books are placed on the lecterns. Fate casts Bless on them. Winter chills the air in the room. Death opens the door (leap of faith needed here, watch them sweat as they realise that the books have effects, and the one they need is Death!)

Then think of a load of books which can have effects, and throw in some red herrings and traps for the party:

• Darkness: Casts the room into darkness.
• Cold: Casts Cone of Cold from the lectern.
• Evil: Summons a devil or demon to attack.
• Fortune & Wealth: The book's a mimic.
• The Labyrinth: rearranges the exit route into a dungeon
• The Dead: Summons zombies to attack (they crawl from below the floor, under the furniture, etc)
• The Sun Also Rises: Bright light.
• Hurricane Irma: Creates a hurricane in the room.
• Eternity: The one who places it is trapped until it is removed from the pedestal.
• The Storm: Lightning and wind and rain.
• Tiamat: Go on. We dare you.

Etc.

Then you scatter these books in the library, along with a load of lore-dump books you've been wanting to offer out (these books just read aloud when placed).

In the rooms behind, there are 3 hidden shrines to the Raven Queen, for her 3 domains. One is intact (Fate), one is damaged and missing a piece, which can be found elsewhere and returned to make it obvious that it is Winter, and then the last is missing, and has to be found and reassembled to make Death.

Clue 1: Religion check.

Clue 2: Find the Shrines

Clue 3: Paintings on the walls which show these three themes. 

After that, you can expect them to seduce the door.

I like that, thanks! I came up with a puzzle and will likely add elements of this to it. The plan is to have 8 bookshelves, each 10 shelf rows high, filled with books. There will be a portrait that changes hanging up, and the picture components will be indicators of the row number, book number from left to right in the row, and the title. Because there will be no indication of which shelf, they will have 8 books to choose from that meet those coordinates and will need to use the clue about the title. 5 books will be obviously wrong with 2 red herrings that correspond to different components of the portrait. 

For example, one portrait will have 3 cages with 4 ravens in each (total of 12) and an eyeball in one of the cages. This will mean that the book is in row 3, book number 12 with the title "The Stolen Eye". However, there will be two other books that will have some title referencing ravens or cages as red herrings. If they open the wrong book, there will be a negative effect (ala the Addams Family library books). The portrait will then change once they find the correct book to show the next clue. 

The clues will get harder because all the numbers will be 10 or less meaning it will be hard to know which one is the row, and which one is the book number. All books from the wrong coordinates will have obviously wrong titles but still have negative effects if opened. 

Also, each of the correct books will summon a ghost, a banshee, and an allip respectively to provide information to the party about the quest the Raven Queen is sending them on. Each with a fun add on of horrific visage, deathly wail, and howling babble. They won't be attacked further and once the spirit imparts their knowledge and screams at them, they will leave.

I have a hard time knowing if my puzzles are too hard or too easy (I know maybe an impossible thing to know) but any feedback is helpful.