 When Chell awakens , GLaDOS claims to have learned " valuable lessons " about humanity from the remnants of Caroline , then deletes Caroline 's personality files and reverts to her usual attitude , but decides that Chell is not worth the trouble of trying to kill , and releases her . Chell then traverses the building in an elevator , serenaded by the laboratories ' robotic sentinels in a song entitled " Cara Mia Addio " . On the surface , she enters a wheat field from a corrugated metal shed , with the charred and battered Weighted Companion Cube , supposedly incinerated during the events of Portal , thrown after her . 
