Mary, seeing her chance to return to being a human being, eagerly hopped toward the dish with the mouse vial liquid in it. She tried to drink but found it difficult with a beak. After a few attempts, Mary got the hang of it and started drinking quickly.
It didn't take long for the magic to work on Mary's much smaller body. Her feather retreated, thinned and turned a light brown. Soon her yellow feathers had become a soft coat of fur. Still, Mary kept drinking, becoming more mouse than bird.
Mary's wings rotated around forward and Mary felt paws beginning to emerge from their ends. She gripped the edge of the dish and put her whole head in to drink deeply. Mary's furred bird tail thinned and elongated into a pink tail. It felt like her tail was being stretched like a piece of clay. The last to change was Mary's head. The oddest feeling was her ears come right out of the side of her head. Huge, thin membranes of skin. It was so very different from both her bird ears and her human ones. These were like two large sails attached to her face. Mary shook her head, and felt her beak soften and stretch into a muzzle with a bunch of long whiskers at the end.
Mary had only drunk half the liquid, but was now a complete mouse. Mary the mouse, walked around the cage, thinking of what to do next.