From that point on, she made it her goal to find a way to keep him alive without subjecting him to his Ice King form. It took plenty of trial and error, but she finally cracked the case, even though it meant not being able to see her beloved Simon ever again. In the episode 'Betty,' she arrives in a portal from the past and learns the painful truth that Simon will soon die without the Ice Crown prolonging his existence. This decision, while heartbreaking to witness, ultimately completes Betty's longtime mission of keeping Simon safe. Thus, she fuses with GOLB and departs into the cosmos.

With their host weakened by the musical ensemble outside, she used the Ice Crown to wish that her love, Simon, was protected no matter what. As the walls closed in and their doom inched nearer, Betty conjured up a plan to escape just in the nick of time. This means that Ice King reverted to his Simon Petrikov persona and Betty loses her magic, leaving the trio helpless to escape digestion. In the confusion, Betty, Ice King (Tom Kenny), and Finn end up inside GOLB and are broken down into their essential forms.

Simultaneously, Fern dies without the Grass Demon to keep him alive, leaving behind a seed in the shape of the Finn Sword. In his stead, she legitimately calls for a truce with PB and the Candy Kingdom. Luckily, Aunt Lolly (Maria Bamford) steps in and uses the serum to turn Gumbald back into Punch Bowl. Conniving as ever, it's revealed that Gumbald had a vial of Dum Dum Juice on hand to turn his niece into a hapless candy person. Now awakened from their slumber, Bubblegum and Gumbald prepare to end their war.

Allies once again, they defeat the entity together and end their rivalry once and for all. Meanwhile, Fern and Finn go head-to-head, but then team up to face the Grass Demon that has warped Fern's mind. In response, he calls off his attack on the Candy Kingdom's forces. She apologizes for turning him into the happy-go-lucky Punch Bowl using Dum Dum Juice, and for not allowing him to further his vision for the Candy Kingdom. In their trance, Princess Bubblegum and Gumbald clash in the Dream Realm, but they eventually put their feud to bed.

Adventure time 3 ice age