Total rumor and speculation at this point, but this part would be fatastically sparse and chill-inducing;
At one point, the music "swells up into full orchestral piece" and a voice of a female character speculated to be Daily Ridley's-says "Wake Up."
http://au.ibtimes.com/articles/573301/20141119/star-wars-force-awakens-trailer-spoilers-leak.htm