For the first book, teleport to the northeast of Enkanomiya, to the teleportation waypoint on Evernight Temple. Go down to the ledge is just below the teleport point and use the switch to make sure you’re in Whitenight, not Evernight.
Like in the Lotus Eater quest, you will need a Geo character to press certain switches in Enkanomiya. Turn on the switch behind the Evernight switch, and it will start spinning a maze. Head to the right of that switch to find another one and turn it on. Once done, use the switch to go back to Evernight. The walls of the labyrinth will light up and you can navigate it.
Head to the left side of the maze on entering and flip the switch here using a Hydro character. Come back to the passage heading towards the center of the maze and take the first right to find another Hydro switch at the end. Go back to the previous passage once more and head deeper in again, over the grid in the center of the maze and behind to find the third Hydro switch. The last switch is at the back of the maze, again accessible from the gate. This will open up the grid in the center, allowing you to dive below. There is a spirit here who you can talk to who will help you find the first lost book.
Once you have chatted with the spirit, you will have a marker on your map in The Serpent’s Heart. Go ahead to find a gate and open it with the key the spirit gave you – the switch is on one of the four pedestals surrounding the gate. This opens up a rather tricky puzzle. Follow the instructions below in detail:
- Change to Whitenight using the switch in the room, then open the doors in the center of the room using the two switches on the pillars at opposite ends of the room.
- Use the Geo switch on the right side of the room (when you turn away from the Whitenight / Evernight switch). Activate it twice.
- Use the door switch closest to the Evernight Switch, then use the Geo Switch twice on the other side of the room.
- Aim the switch on the opposite door, turn it on, then use the Geo switch on the other side of the room just once.
- Return to Evernight, and it will unlock a chest containing the item the spirit wanted.
After all of that, come back to mind, and he’ll give you what you need to open the door just down the stairs from him. Inside is a chest that contains the first lost book. Phew.