The portal gun backfired onto you, forcing you through a portal before it had the chance to fully develop. Suddenly, you were shot out the tiny portal.

As you flew through the air and eventually landed on the floor, you felt multiple heavy footsteps approaching.

GLaDOS: "Hello? Where are you? I know you're there... I can feel you here."

Her thundering steps caught up to you, nearly crushing you, but stopping short. Her feet are so huge next to you...

GLaDOS: "Ah... There you are. Care to explain how you got so small?"