It is based on Alice's Adventures in Wonderland and Through the Looking-Glass by Lewis Carroll.
Betty falls asleep doing a jigsaw puzzle of Alice and the white rabbit.
She "awakes" just in time to follow the rabbit through the looking glass and disguises as Alice into a modern wonderland.
Betty meets most of the traditional inhabitants of Wonderland and sings "How Do You Do" (to the tune of "Everyone Says I Love You") to them.
Betty wakes up back in her living room, just in time to prevent the white rabbit from again escaping from her puzzle.