What Was Missing

Synopsis
Finn and his friends must come together and play music as a genuine band in order to open the gate of the Door Lord and retrieve their stolen items.

Plot
The scene opens to Finn checking to see if no one else is home before pulling the lock of Princess Bubblegum's hair from the episode,"To Cut A Woman's Hair" out from under the couch. He sits down and cuddles with it until Jake comes out from behind the couch with BMO. Jake tells a startled Finn that he already knows about his "private time he spends with the wad of Princess Bubblegum's hair." Jake then picks up a floor board and pulls out his baby blanket to show Finn a special object of his own. Then a door appears and out hops a Door Lord. He snatches Finn's wad of Princess Bubblegum's hair, BMO's controller, and Jake's blanket. The three follow the Door Lord through a door that leads to Princess Bubblegum's castle, where she is seen running after him and demanding that he come back, yelling "Get back here you theiving door lord!", which helps identify the creature to Finn and Jake. The Door Lord then opens another portal, which Finn, Princess Bubblegum, BMO, and Jake follow through into Marceline's house. Marceline is trying to hit the Door Lord with her bass, until he opens up a final door that hurts Marceline with the sunlight through it. The group, now with Marceline, who has put on a pair of gloves and a sun hat which will protect her from the sun, and Princess Bubblegum, go through the final door into "Red Rock Pass," chasing the Door Lord until he escapes into a double door that closes in front of the four. Finn then reads the words that appear on the archway that say: This door shall yield to no command save for a song from a genuine bande.

The crew then tries making some music to tempt the doors to open using their assorted instruments, but when Marceline begins to sing about wanting to "drink the red from your (Princess Bubblegum's) pretty pink face" Princess Bubblegum comments that her lyrics are "too distasteful." Marceline then replies defensively, "Oh, you don't like that? Or do you just not like me?!" She then sings a song mocking Princess Bubblegum, sarcastically apologizing for not "treating her like a goddess" like the princess's "loyal little subjects" and not being "made of sugar." Bitterly, Marceline sings "I'm Just Your Problem" to Princess Bubblegum, inducing shocked reactions of silence from the princess, Jake, and Finn. Since the door reacts to the truth (later realized by Finn) and the door reacted to her song, the lyrics to Marceline's rock ballad consisted of her true feelings. At the end of her song she stumbles, stammering something that isn't truthful ("to...to bury you in the ground... and drink the blood from your... urgh!") causing the faces on the door to stop responding to the music, and to dim. Marceline then yells "Stop staring at me!" Which may be a hint of her embarrassment.

Jake calls Princess Bubblegum and the others "talentless hacks" and leaves, only to come back again later (this is all part of his act as the band's self-proclaimed jerk). Finn suggests that they have a noodle break, taking a pack of dry, uncooked noodles out of his backpack. Marceline then starts to float off to the open door that the Door Lord left open, and Finn says in a panic: "No! Wait- don't go too!" Thinking that Marcy has decided to leave the band as well, but Marceline just tells him she's getting something to cook the noodles.

Finn continues to eat the noodles raw. Marceline comes back, with a pot and a mobile stove, and tells BMO "come here baby," and hooks BMO up to heat the pot of water, and Finn drops his noodles into the pot. The sun goes out, and Marceline takes off her hat. When Finn suggests a song about noodles, both girls say "No!" In unison, to which they all laugh shortly afterward.

Princess Bubblegum then tries to make a new song, and Jake comes back. Jake says: "Shut yo face, I came back for the MUSIC." After Princess Bubblegum's plan fails due to her "miscalculations" Marceline says that Princess Bubblegum wasn't as perfect as Princess Bubblegum had thought, and that PB couldn't judge her anymore.

The two have a fight. Marceline then spits on Princess Bubblegum's jacket, and they all begin to leave, except for Finn. Finn then begins to sing a song of what his best friends think of him. Marceline, Princess Bubblegum, and Jake join in as Finn sings about how they were all "best friends in the world." The door, in response, opens to the Door Lord eating a sandwich in an empty room. The crew listens to his mumblings, and while Finn appears to be perplexed at them, Princess Bubblegum, Marceline, and Jake state that what the Door Lord had hoped for them to learn, that the real treasure was their friendships. The Door Lord smiles with glee at their revelation, but then he is shortly beaten up afterward by the five, presumably in retaliation to his thievery. Jake then passes out their stolen items. Finn receives his wad of Princess Bubblegum's hair, where Princess Bubblegum replies, "Oh, you." and Finn mutters under his breath "Yeesh." Jake gets his baby blanket and BMO gets its controller back. A black tee shirt with what seems to be cinnamon rolls strangling a snake is mistaken to be Marceline's, but is claimed by Princess Bubblegum; claiming she wears it all the time as pajamas causing Marceline to blush. At the end, it is revealed that the Door Lord hadn't actually taken anything from Marceline, she was lonely and just wanted to hang out with them. She vehemently denies this only for Finn to tease her about it. The episode ends with Marceline in a monster form chasing after Finn, Jake, and Princess Bubblegum exclaiming, "I'll kill you!"

But Finn, Jake and Princess Bubblegum run out laughing as Marceline chases them.

Major Characters

 * Finn
 * Jake
 * Princess Bubblegum
 * Marceline
 * BMO
 * Door Lord

Minor Characters

 * Shelby (cameo)
 * Snail
 * Jam Jam
 * Cloud Person

Songs

 * "I'm Just Your Problem"
 * "A Song About Noodles"
 * "Bubblegum's Blueprint Song"
 * "My Best Friends in the World"

"Mathematical!" controversy

 * For information on the controversy surrounding the "Mathematical!" video related to this episode, see: Mathematical!

Trivia

 * This episode was formerly titled "Door Jam." Adam Muto confirmed that it was the working title. It was a pun on the musical term "jam" and on "door jamb," the name for the vertical part of a door's frame. However, the title was changed because the Adventure Time writers prefer not to use puns in episode titles.
 * The very first scene of this episode shows the back of Finn's house, instead of the front. You can see a telephone wire and a garden.
 * The oven, range hood, and cabinets in Marceline's house are now white instead of red (the color they appeared in previous episodes).
 * The title card was designed by Michelle Xin and painted by Martin Ansolabehere.
 * Shelby is seen crawling out and back into Jake's viola when he smashes it.
 * This is the first time in an Adventure Time episode where Princess Bubblegum sings.
 * At the end when Princess Bubblegum is seen running away, her shirt is magenta instead of black and her dress was purple instead of pink.
 * At the end of the episode when Marceline is chasing everyone, BMO is not seen with them. This is more likely a continuity or an animation error.
 * This is the first episode with Princess Bubblegum and BMO interacting.
 * The Door Lord looks similar to Key-per from the episode "The Enchiridion!." Key-per wore a key strapped to his head while the Door Lord wore a door.
 * While Princess Bubblegum, Finn, and Jake are chasing the Door Lord in Marceline's house, the title card music for "Hitman" plays.
 * During Marceline's song, you can once again see that "toots" is written on the back of Jake's viola, which was first seen in the episode "Gut Grinder." And in "My Two Favorite People," Jake calls Lady "toots" when he's putting the universal translator on Lady.
 * This is the second episode where Marceline cries, the first one being "Memory of a Memory."
 * When Princess Bubblegum plays 8-bit music on BMO, it is playing music from the original Megaman games.
 * In most of the scenes, Princess Bubblegum's hair band changes colors.
 * When Marceline plugs in the heater into BMO, the plug is two-pronged while the plug-hole is a singular round hole, yet it still fits.
 * If you look closely to the Door of the Door Lord, you can see that the word band is written in "Bande," which is French for "Band."
 * When Princess Bubblegum's song fails she says "I seem to have... miscalculated." This may be a nod to the original Star Trek series. It is listed on IMDB as a memorable quote from Se2Ep10 Journey to Babel. In that episode the line is delivered with the same delay between "have" and "miscalculated."
 * When the Door Lord steals a candy kid's toy, Finn jumbles the words up and mispronounces his line, shouting "I'll get your kid back, toy" instead of "I'll get your toy back, kid."

Censorship

 * This episode was censored on Cartoon Network Australia. See Censorship of Adventure Time in Australia for more information.

Videos
Video:"What Was Missing" Animaitc|Animatic ((Mark)) appeared.