|The following information is from the Adventure Time comic book series.|
It may not be part of the same canon or continuity as the animated series.
Issue 17 of the Adventure Time comics.
Ice King uses his ice powers to make the ice clearer so they can see what's below them, and Fisho the Colossal, the Ice Dungeon boss, bursts out of the ice and attacks them. Finn and Ice King defeat the monster (the injuries causes her guts to shower onto Finn twice), and she explodes.
Remembering that water bosses always hide their treasure underwater, Jake turns into a submarine and takes Finn and Ice King underwater to get the treasure. They find a chest that has a picture of Simon Petrikov and Betty that causes Ice King's eyes to water in joy. He explains to Jake that it's the kind of treasure you can't take with you, but you know you can always come back to it.
They leave Ice King's dungeon and enter Hunson Abadeer's dungeon. As they enter it, they find Peppermint Butler carving an inscription on the inside of a hollow tree. They think it's an incomplete story and carve in their own edits to it.
As they progress through the dungeon, they find the enemies really easy to dispatch, tossing them into a pile of bugs. They form a fist and knock them into a trap door, and they are attacked by the monster Hook Crook, who beats both Ice King and Jake. Finn prepares for battle to fight Hook Crook alone, leaving the issue on a cliffhanger.
But before the issue ends, we see that the picture of Simon and Betty at what appears to be a wedding has a quote from Alfred, Lord Tennyson's poem In Memoriam A.H.H. on the back: "Behold, we know not anything; I can but trust that good shall fall. At last - far off - at last, to all. And every winter change to spring. So runs my dreams: but what am I?"
Back up Story
Silly String Theory
Princess Bubblegum has invited Finn and Jake to see her newest experiment, the Silly String Theory Device. She built it on her theory that silly string is a fundamental cosmological force (at least in the Candy Kingdom) and she needs Finn and Jake to guard it while she goes to the library so that it isn't sabotaged before the big science conference.
Later, Finn and Jake are guarding the device when Finn get the desire for some gum and Jake suggests the silly string in the device since it looks like gum. Finn chews it and blows a bubble which has it's own universe inside it.
Just as the two are looking at the inside of the bubble, however, Dr. Broccoli, Princess Bubblegum's completely unknown rival, arrives with his robot brussel sprout minions to destroy the Silly String Theory Device. Jake goes inside the bubbleverse for help and Finn fights Dr. Broccoli with Princess Bubblegum's weeping blade (a sword that constantly cries and is verbally against violence). Jake arrives from the bubbleverse in a tiny flying saucer with an alien named Blergal who shapeshifted into Dr. Broccoli's mom and make him eat his brussel sprout minions and go to his room.
In order to solve the problem of the bubble still in Finn's mouth, Blergal then tells the duo that the silly string universe is made of "What The?" matter. If they think happy thoughts while screaming ""What The--?" the universe will turn into fireflies. They do so and the bubble turns into four fireflies.
Silly String Theory
- The raccoon by the campfire on the cover bears a striking resemblance to the character Rigby from Regular Show, although it has only four stripes on its tail while Rigby has six. It also has fewer lines on its body and lacks rings around its eyes.
- In "Silly String Theory," Finn references Spearmint gum.
- The alt-text on the main story's last page ("And with no language but a cry.") is from the same poem as the lines on the back of the photograph.
Comic preview pages and panels