|This article is about the episode. You may be looking for the character.|
The episode begins with Finn having a dream about the Cosmic Owl screeching, Billy kissing his lady, and the bear and the snail reading the Enchiridion. At one point, while he is laughing, Billy's image flickers to The Lich and back again. Suddenly, the snail kills Billy and Finn wakes up. He tells Jake about his dream and Jake says it is a premonition dream. He then says they should go tell Billy because he was in the dream and then drives Finn to Billy's Crack.
Once there, Billy yells at them saying that its 3 in the morning and asks why they are there. Finn says that they wanted to make sure he wasn't dead, to which Billy asks why they would think that, and Finn proceeds by explaining about the dream. Billy asks them if they want to save all life from the Lich and they agree. After they head out. Billy tells them that they need to collect all the magical gems from all the princesses and Ice King's power crystals that protect them from the Lich.
After some time spent collecting crystals, the group stops to rest for a bit and Jake asks Billy how many more crystals they need. Billy indicates that there is 1 left. Finn gets hungry and rummages through Billy's knapsack looking for candy, finding the Enchiridion after being smacked out by Billy and asking why he had it. Billy says that he found it in the mouth of a bear and Finn blushes with embarrassment as he remembers giving the book away to the bear. Billy says it has magical powers and tells him to turn the sword on the cover of the book which Finn does. The circle on the front opens up showing 9 slots where all the gems go in mystically (except Lumpy Space Princess's whom just falls over the book) and shows a brief diagram about what would happen if all the slots where filled. At first, Jake and Finn wonder what all the holograms are, but Billy uses the blue crystal on his face to activate another hologram. A man named Book-o (who bears a resemblance to a Key-per) appears and explains what the first set of holograms represent, which is all the known universes and dimensions, and how they are connected. Jake tries to play around with it, but it frightens him and he calls it off. Book-o goes on to mention that in the center of the universe is the Time Room where Prismo dwells. Billy states that he's going to push the Lich into there, seemingly to place the Lich in non-existence.
They then go to the Candy Kingdom to get Princess Bubblegum's crystal (she is experimenting with little creatures, cutting off their legs and reattaching them) and Finn breaks through the roof and asks for the crystal on her crown. Princess Bubblegum is shocked and refuses, and Finn tries to grab it by force, during which Princess Bubblegum accidentally slices Finn's cheek with the scissors she is still holding from her experiments.They stare at each other for a brief moment, both stunned, and Princess Bubblegum says "That was an accident." Finn hisses, removes the gem aggressively from her crown and runs off with it with Princess Bubblegum not far behind. Once outside, he then puts it in the final slot and the book's pieces start to fall off as the Enchiridion turns black (or to some rock-looking substance). Princess Bubblegum runs out telling him that Billy is really the Lich and not to give him the book.
Just as she says this, one of the Gumball Guardians gets up and blasts Billy, detecting the Lich's presence, thus revealing half of the Lich's true face. The Lich then asks for the book. Finn realizes that the Lich "messed Billy up" and after dodging a grasp from him smashes the book with his knee, but that action accidentally opens up a wormhole, to which the Lich is pleased and thanks Finn, tauntingly. As the Lich tries to pass through, Jake grabs him, reacting to Princess Bubblegum's request, and stretches as to not go through. Jake, though, is slowly dragged into the portal as the ground under him gives way. Finn tries to stop Jake from getting pulled in but instead is pulled in with him. The episode ends with a boy who looks similar to the Finn (but looks like the version of him from the floor mirror in "King Worm"), playing his flute with a regular dog who looks just like Jake, then his mother (Who is temporarily named: Finn's Mother, until further notice) calls him in for what she says is "something important" and the episode ends mysteriously as he heads inside with his dog.
- Finn's Mother
- Booko (The Enchiridion)
- Ice King
- Gumball Guardian
- During Finn's dream, when Billy is laughing he switches to the Lich in one frame then back.
- On the back of the Enchiridion, three numbers from the Fibonacci sequence can be seen.
- Lumpy Space Princess' royal star does not possess magic similar to the gems of Ooo royalty. Instead it makes her fly, and is seen falling to the side instead of taking a place in the circle of magic gem holes in the book. It is unknown if it protects Lumpy Space Princess from the Lich's mental control like the other gems.
- However when the gems were drawn to the book Lumpy Space Princess' gem was pulled by the magical force.
- The computer monitor that Finn is looking at in his dream has a similar appearance to an iMac G3.
- Billy never physically touched the gems, which was foreshadowing that it was not Billy, but the Lich. When Finn tried to let Billy carry a gem, he refused.
- In Finn's dream, when the Lich goes in Billy's body, he goes through his heart located beneath Billy's beard.
- On the Enchiridion's lock appears Tolkien's elven alphabet.
- In the portal, a shred of land appears to be in the shape of Texas.
- When the Lich (as a snail) is reading an enchantment in Finn's dream, a page flies in front of Billy's face. This page is the first page of Chapter 5 ("How to Kiss a Princess"), which was first seen in "The Enchiridion!"
- "Ex Hibio Conatum" which Billy chants to reveal the holographic map means "Prohibits from Attempt" in Latin.
- The gems used for the Enchiridion match with many of the characters that Finn and Jake take them from; however there are several gems that don't match any known characters, including a deep blue, yellow and violet gem. A light green gem is also seen, however three potential princesses possess the gem whom they could have taken it from: Slime Princess, Jungle Princess or Turtle Princess.
- The barn in the alternate dimension has multiple gears which gives it a futuristic look.
- The tapestry with the unicorn in Finn's dream is based on "The Unicorn is in Captivity and No Longer Dead" which is part of "The Hunt of the Unicorn," a series of famous tapestries. The four dogs in the cave could be same as the one on "The Hunters Enter the Woods" tapestry.
- Princess Bubblegum playing around with the little clay/candy people and cutting them up could be a reference to the Adventures of Mark Twain.
- Booko's speech on Portals references the video game Portal. When the holographic person pulls on the string and the portal opens it makes a similar noise.
- When Booko talks about "items of great power," a hologram of someone using a paddle ball is shown.
- When Finn mentions the Cosmic Owl was in his dream, Jake claims it was a premonition dream, similar to his own in "The New Frontier."
- This is Billy's first reappearance since "His Hero."
- The strange-looking Finn appears when Finn looks in the mirror in "King Worm" indicating that the mirror might have looked into alternate universes.
- The bear returns for the first time since "In Your Footsteps."
- Book-o resembles the Key-per from "The Enchiridion!" and the Door Lord from "What was Missing."
- The flute that Finn is playing in the alternate universe at the end of the episode is also seen in "Prisoners of Love," although the flute looked more damaged before Finn threw it, which caused it to break.
- The barn and house in the background of the alternate universe is seen in Memory of a Memory when the Youngest Marceline is shown.
- Finn claims that in his dream, the Cosmic Owl was on television; however, he was actually viewing it on a computer monitor. However, this may be attributed to Finn's laid-back vernacular or it could actually be a television.
- Though Billy is normally seen to have 6 fingers (5 and a thumb) on a single hand, when he picks Finn up to ask if he's ready for the next adventure, Finn appears to be standing in a hand with 7 fingers (6 and a thumb). This could just as easily be a bit of additional foreshadowing that it wasn't actually Billy, but for the rest of the episode, "Billy" has 6 fingers (easily seen while eating a sandwich or while preparing to jump in the snow).
- When Finn realizes that Billy is the Lich, Jake's nose is the color of his skin; not black
- When Finn goes inside Billy's saddle bag and gets slapped out it disappears for a second.
- When Princess Bubblegum reattaches the little creature's limbs for the first time and sets him down, his right arm is missing; it reappears when he falls over.