It was a great day in Aperture for Chell, if you could call any day in Aperture great.
Aperture is a testing facility. It's also the only place Chell remembers.
There were no turrets, GLaDOS wasn't speaking much and the test chambers were strangely easy. Not as easy as walking to the door, but as if someone had altered it slightly to make it easier.
she was walking through the door, when the platform below her started moving and all that was under her was a toxic pool. Luckily it was slow, so she had time to get through the door.
If there was a door.