 Chell wakes in a stasis chamber resembling a motel room , where an artificial voice guides her through a cognitive test before she is put back to sleep . When she awakens again , the Aperture Science complex has become dilapidated and overgrown and appears on the verge of destruction . Wheatley ( Stephen Merchant ) , a personality core , helps her attempt to escape via the test chambers . In the process , they accidentally reactivate the dormant GLaDOS ( Ellen McLain ) , who separates Chell from Wheatley and rebuilds the laboratory . 
