She could have left, have gone far away from the facility. Instead GLaDoS wanted one last time. To be able to enjoy some more time with Chell. Being Caroline has obviously corrupted her, in a good way. "I'll admit, killing you? Its hard..."
"I'll let you go, towards the freedom you so desperatly want, but before you go, one last test like before when we didn't want to kill each other." Chell crossed her arms and slided some of her weight to her side.
"Trust me, its a special test." Before Chell could agree, her lift was already on her way downards, past multiple test chambers, and finally landing onto one. It wasn't as hard as it looked, but there needed to be a bit more ingenuity. There were no turrets oddly. There was a very large chasm and a light bridge. There was also a large monitor in which GLaDoS could be seen watching Chell through it.
"Now, complete the test." She said and continued watching. Chell looked at her right hand, she held no portal gun. Then there was a large blast and an orange portal appeared behind her, at a white surface. She speeded off into it, gripping the portal gun that was on the rotating pedestal. Now in possession of a portal gun she could use the light bridge to get out, but where? She didn't see the proper exit. There was however the chasm and white surface, so just for a try, Chell shot out a portal to light bridge and plopped it onto the other surface below. It reached the edge as if she was supposed to slide down. She could hear GLaDoS yell.
"Move, I can't see her!" Atlas and P-body were in her way of the monitor. Chell looked back and then slid down the light bridge. When she reached the end, there was in fact ground floor, scattered, but there was ground, and they still led to one place. Down. With the dripping gel she shot from the leaking pipe over to other surfaces she brought herself downwards. A faint orange-red light lit the darkness that she was now in.
When Atlas and P-body finally moved out the way of the monitor, a blue portal bursted onto a wall and out came Chell, holding a round dark-brown cake with strawberries around top rim of it and when she looked up at the monitor, her mouth moved. She finally spoke and it was three simple words.
"Thank you, GLaDoS."
