In “Adventure Time with Fionna and Cake” #6 by Natasha Allegri and Betty Liang, Fionna saves the day and almost everyone except for Lumpy Space Prince gets what they want, but the detail of what happens will surprise readers who followed the story.

The final issue opens with a five-page illustrated fairy-tale sequence by guest artist Betty Liang. It’s an inverted echo of the fairy tale narrated by Cake that opened the miniseries in “Adventure Time with Fionna and Cake” #1. It makes for a fitting book-end to a miniseries about friendship and heroism. Like the fire maiden tale, the story of the river nymph and her friend the cat is melancholic in tone, with themes of sacrifice and love. Liang’s delicate lines and pale colors reinforce the water element theme, and she has a creative repertoire of illustration techniques. In particular, the repetition of the cat’s body in one panel to symbolize its many lives was a clever and attractive touch. However, unlike the fire maiden story, the narrator is unclear and there is no direct tie-in to the present day. Instead, the links to Allegri’s overarching plot are subtler.

Allegri ties up all the dangling plot threads (Fionna’s hair being on fire, the fire booger’s ice-crystal-ticking-clock dilemma) in unexpected ways. The most fascinating plot turn is the fate of the villainess. The Ice Queen, seemingly evil and hilariously vampy and vain thus far, suddenly becomes a three-dimensional character when she answers Fionna’s frustrated question, “Why do you hate me so much?” The Ice Queen’s goodbye scene is poignant and sad, while also being a classic allusion to the fate of witches.

Allegri doesn’t spoon-feed her readers, but upon rereading, the mystery and magic of the Ice Queen’s decision, and the recurrence of the elements and the crystal motif, hint that the Ice Queen might be related to the brave and tragic water nymph of the tale. If true, Allegri has made the villainess the most dynamic character of the story, an unusual move.

The Lumpy Space Prince story in “Adventure Time with Fionna and Cake” #4 seemed to be just a fun detour from the main plot, but LSP resurfaces hilariously for this final issue, providing comic relief after the mystery and sadness of the Ice Queen’s departure. To say more about how LSP helps deliver our heroine into safety would be a spoiler, but it’s both clever and ridiculous.

In the wrap-up action, the fire booger’s new home visually echoes the original fire maiden story. Allegri’s art and colors, assisted by Seery, are as attractively candy-like as ever, and the characters are their endearing selves, consistent and comforting while defying stereotype.

The oddest part of “Adventure Time with Fionna and Cake” #6 is the last two pages, as Fionna and Cake’s animated conversation bleeds into Gunther the Penguin’s chorus of repeated “Wenk Wenk Wenk” sounds. It’s a cute scene, and Gunther is a fan favorite, but it also implies a frame, one in which all these adventures with Fionna and Cake were just a story that Gunther was telling the Ice King. If so, Allegri diminishes or undermines the reality of the world she has created. It’s a strange way to end an unconventional series with such a conventional cop-out framing device.

Still, despite the odd closing note, “Adventure Time with Fionna and Cake” #6 is full of surprises and twists, and it’s also a satisfying, strong ending to a distinctive, excellent miniseries.