No. overall No. in season Title Supervising direction by Written and storyboarded by Original air date Prod. code US viewers (millions) 267 "The Wild Hunt '' Cole Sanchez Sam Alden, Erik Fountain & Polly Guo September 17, 2017 (2017 - 09 - 17) 1054 - 275 0.77 Still feeling guilty over Fern 's death, Princess Bubblegum tasks Finn to protect the banana guard from a monster later dubbed "the Grumbo ''. Finn ca n't bring himself to slay the monster as he keeps seeing Fern 's face materialize when he 's close to defeating it. Later, Finn meets up with Huntress Wizard (voiced by Jenny Slate) who is also trying to slay the Grumbo and she tries to give encouraging words to Finn. They find the Grumbo 's cave and Finn once again stalls. Huntress Wizard puts herself in harm 's way and Finn imagines Fern in her place and finally slays the Grumbo. Afterwards, Finn and Huntress Wizard casually admit their feelings for each other and realize that the Grumbo was artificially created. Uncle Gumbald plots to create another monster using the remains of Fern. 268 "Always BMO Closing '' Diana Lafyatis Graham Falk & Kent Osborne September 17, 2017 (2017 - 09 - 17) 1054 - 273 0.77 BMO and Ice King become door - to - door salesmen by posing as one body (Ice King as the body and BMO as the head). After selling a stick to Tree Trunks, the two get lost and end up at the dungeon where Gumbald is staying. They sell him Finn 's baby teeth which he happily pays for with a silver cup. Finn is outraged that his baby teeth were sold and is further mortified when Baby Finns made of teeth begin attacking the tree house. Through Ice King 's encouragement, BMO "sells '' two mallets to Finn and Jake and they successfully defeat the teeth babies. Afterwards, Gumbald admits that his current plan was a bad idea. 269 "Son of Rap Bear '' Diana Lafyatis Seo Kim & Somvilay Xayaphone September 17, 2017 (2017 - 09 - 17) 1054 - 276 0.77 While at a party, Flame Princess accidentally signs a contract from Toronto stating that if she loses in a rap battle against Son of Rap Bear (voiced by Dumbfoundead) her kingdom will be forfeited to Toronto. She and Finn go meet Rap Bear (voiced by Rekstizzy) who explains that his son literally blew his legs off, frightening them. Despite training, Flame Princess still feels ill - prepared, and so she visits her father, the deposed Flame King (voiced by Keith David). She attempts to mend their rocky relationship, but much to her frustration, her father seems oblivious to the pain that he caused his daughter. Later, at the rap battle, Flame Princess begins to lose her composure, but after seeing the still - unapologetic Flame King in the crowd, she angrily expresses her frustrations with her father in a rap. The track impresses the crowd, and Flame Princess defeats Son of Rap Bear. 270 "Bonnibel Bubblegum '' Diana Lafyatis Hanna K. Nyström & Aleks Sennwald September 17, 2017 (2017 - 09 - 17) 1054 - 274 0.77 When Finn presents the silver cup from "Always BMO Closing '', Princess Bubblegum decides to tell him, Marceline and Jake some more of her history. 800 years ago, a child version of Bonnibel discovers a family photo and decides to create a gum family. She creates Uncle Gumbald, Aunt Lolly and Cousin Chicle to help farm the area. But her family quickly turn on her with Gumbald wanting to "brand '' their family as he creates a juice that transforms its drinkers into low minded candy people. Bonnibel fights back with her family transformed by their exposure to the dumdum juice into the first of her candy citizen and deciding on the title of princess. In the present, BMO reveals where it got the cup. 271 5 "Seventeen '' Cole Sanchez Seo Kim & Somvilay Xayaphone December 17, 2017 (2017 - 12 - 17) 1054 - 281 0.76 At Finn 's seventeenth birthday party, held at the Candy Kingdom, Princess Bubblegum, Marceline, Huntress Wizard and BMO present Finn with gifts. Suddenly, the Green Knight (voiced by Brad Neely) arrives and presents Finn with his own gift, an ax that he will reward him with if he attacks him with it. Thinking this is one of Jake 's tricks, Finn beheads the Green Knight only for Jake to arrive and the Knight challenges him to a battle by blocking him from his friends. Finn accepts and the two play 2 / 3 with the party games held at the castle. While arm wrestling, the Knight reveals himself to be a revived Fern who makes short work of Finn. He is stopped by Gumbald, who reveals that he, Lolly and Chicle were all restored from being exposed to Lumpy Space Princess transforming Ooo at the end of Elements. The trio and Fern leave as Finn is devastated by his loss. 272 6 "Ring of Fire '' Cole Sanchez Tom Herpich & Steve Wolfhard December 17, 2017 (2017 - 12 - 17) 1054 - 277 0.76 Tree Trunks gets a call from her old flame Randy (voiced by David Herman) who wants his old ring back to propose to his new girlfriend. In flashback, Randy proposed to Tree Trunks after graduating high school. Immediately afterwards, Tree Trunks left him and became a pirate on the sea where she met and married Danny (voiced by Raza Jaffrey). She breaks up with him due to him lying to her and she moves on to becoming a CEO to a shipping company. She marries her employee Wyatt, but due to his clinging attitude breaks up with him and he flees with the ring. Mr. Pig, who followed arrives as does Wyatt who still has the ring. Randy gets it back and Tree Trunks and Mr. Pig reaffirm their love. 273 7 "Marcy & Hunson '' Cole Sanchez Graham Falk & Adam Muto December 17, 2017 (2017 - 12 - 17) 1054 - 278 0.76 Peppermint Butler gives Finn a new sword, the Night Blade. However, he also summons Hunson Abadeer. Peppermint Butler allows Hunson to roam the earth for one day and is restrained from using his powers. Finn and Jake take him to Marceline who is once again annoyed at her father 's ignorance. When Finn and Jake let slip that Marceline has a solo concert for ghosts, Hunson forces his way in. Marceline gives her performance, but it is interrupted by Hunson 's interference. Chicle, who has been following them, instigates a ruckus with the ghosts who proceed to beat up a weakened Hunson. Marceline is also powerless from stopping them, but Finn 's new sword saves them. The group escape and meet with Princess Bubblegum and Marceline and Hunson make up. 274 8 "The First Investigation '' Diana Lafyatis Hanna K. Nyström & Aleks Sennwald December 17, 2017 (2017 - 12 - 17) 1054 - 279 0.76 Kim Kil Whan sends Finn and Jake to Joshua and Margaret 's old office after one of his employees get frightened by something. Finn and Jake witness strange ghosts and other sightings as objects move around. Finn suddenly sees baby versions of himself, Jake and Jermaine and gives Jake a wet willy (earlier Jake claimed that Finn had given him one years ago and he denied it). Realizing that the ghosts are time remnants, Finn tries to look for the source while Jake accidentally scares Kim 's employee and sees his own birth from "Joshua and Margaret Investigations ''. They discover that one of Dr. Gross ' experiments, Time Bear, had been behind it and fix him with Finn leaving a note for past Joshua and Margaret. While outside, Jake meets his alien parent, is turned blue and taken away leaving a note for Finn that reads "BRB - Jake ''. 275 9 "Blenanas '' Diana Lafyatis Sam Alden & Patrick McHale March 18, 2018 (2018 - 03 - 18) 1054 - 280 0.53 Bummed about Jake being gone, Finn reads an issue of Ble Magazine and comes across a doodle of a caveman with his leg getting bit by a dog while a psychiatrist sits next to him. Finn writes "Ouch! Hey this is n't helping at all! ''. He shows it to BMO and Princess Bubblegum, but neither get it. Finn shows it to Ice King who reveals that he wrote to Ble Magazine to have his stories published, but they never were. They find the building guarded by a passive pudding troll and discover that the building has been abandoned for years. They decide to publish a new issue with the joke, but the pudding troll does not get it either. Finn comes to terms with the possibility that he just is not funny, but upon returning home he slips on some banana peels, rips his pants and crashes into a message chair. BMO and NEPTR laugh as Finn smiles. 276 10 "Jake the Starchild '' Cole Sanchez Hanna K. Nyström & Aleks Sennwald March 18, 2018 (2018 - 03 - 18) 1054 - 283 0.53 Immediately after "The First Investigation '', Jake is taken by his dying alien parent, Warren Ampersand, to his home planet and discovers that he must defeat an evil alien to save the inhabitants. Warren gives Jake a special belt while he wears one himself. As Jake uses his stretching powers, he becomes weaker and Warren becomes younger, revealing that the belts drain Jake 's youth and energy. When Warren reveals his scheme as well as the fact the planet and evil alien are not real, Jake switches the belts and tricks Warren into giving his powers and youth back. Warren then tries to escape back to Earth after learning that Jake has children he could siphon from, but Jake tosses him into a black hole, leaving him stranded on the now empty space rock. 277 11 "Temple of Mars '' Diana Lafyatis Tom Herpich & Steve Wolfhard March 18, 2018 (2018 - 03 - 18) 1054 - 282 0.53 Finn is visited by Jermaine who reveals that Jake is in space and that they must rescue him. They head to Mars where Normal Man, now King Man, has Betty doing labor to "cure '' her. King Man has them enter a cave to search for a device to save Jake and encounter various puzzles. Eventually, they come across Past Betty who was to go on a trip in a week, but met Simon changing her plans. Finn and Jermaine tell her that Betty needs to think about herself and she "changes '' her past so that she left that day instead of in a week. The cave turns out to be the device and they are reunited with Jake. However, Betty tells King Man that seeing Finn retrieve Jake has only increased her interest in rescuing Simon; she declares that she now has a plan to not only save Simon, but also retrieve Margles from GOLB, which frightens King Man. 278 12 "Gumbaldia '' Diana Lafyatis Sam Alden & Graham Falk March 18, 2018 (2018 - 03 - 18) 1054 - 284 0.53 As Princess Bubblegum prepares for war with Gumbald, Finn and Jake decide to visit him to prevent the battle from happening. They meet with the Gum Family who are hellbent on wanting to destroy Bubblegum. However, when Finn saves Gumbald from falling, the family come on good terms with Finn and Jake and sign a peace treaty. Before leaving, Finn and Jake are doused with celebratory juice. When they get back to the Candy Kingdom, the juice turns out to be dumdum juice and turns Peppermint Butler into a baby. With no other option, Bubblegum sets to go to war with her uncle. Gumbald learns of Bubblegum 's survival and gathers forms an alliance with numerous past villains from throughout the series, including a confused Ice King, in preparation for the Gum War. 280 281 282 283 13 14 15 16 "Come Along with Me '' TBA TBA September 3, 2018 (2018 - 09 - 03) TBA TBD BMO narrates the Great Gum War in which Princess Bubblegum, Finn, Jake, Lady Rainicorn, Marceline, Flame Princess, Lemongrab, Slime Princess, Duke of Nuts, Huntress Wizard, and Lumpy Space Princess band together to battle Gumbald and his army.
when is the last episode of adventure time going to air
September 3, 2018