Ursula introduces herself as a witch who explains that, with Triton's trident, she can grant Ariel's wish to see other worlds. Ariel takes Ursula to the palace, where she is given the trident. King Triton enters, shocked at Ursula's reappearance. He orders the witch to return the trident, to no avail. Ursula attacks Triton, turning him into a sea urchin. Ursula adjusts her attention to Ariel, saying she is indeed going to a new world: the dark world of the Heartless! Before that, though, Ursula asks Flotsam and Jetsam where the Keyhole is. Hearing their failure, Ursula swims away to find it, passing Sora and company in the process. The group enters the palace, forcing Sebastian to explain what happened. Sebastian explains Ursula is after the Keyhole. Immediately, the group leaves to follow Ariel.
They catch up to Ariel at the Sunken Ship, where they are ambushed by the Shark. The Shark goes after Goofy, clamping down on his shell. This shatters the shark's teeth, forcing the shark to whimper away. The group finds a movable rock, leading down a passage. The group follows it, eventually finding Ursula's lair. Ursula uses the trident to attack the group, accidentally misfiring and destroying Flotsam and Jetsam. Enraged, Ursula uses her power to grow to an enormous size, claiming herself the ruler of the sea.
(Numbers indicate order of appearance.)
Items of note
Kingdom Hearts references