when wheatley cannot get the result he wants from the tests, he decides to kill chell and glados. they escape and eventually find him, leading to the final fight. glados helps chell attach broken personality cores to wheatley to weaken him and she tries to press the button that switched glados and wheatley in the first place. when she is unable to, she shoots a portal on the floor below wheatley and another on the moon, which can be seen through a hole in the roof. wheatley is pulled from glados's body and released into space. chell is almost pulled out too, but glados saves her and closes the portals.