The 4 night Heroes v Aliens crossover event kicks off with a new <a href="/hashtag/supergirl?refid=13&__tn__=%2Cg"> <span > #</span><span >Supergirl</span></a>, TONIGHT at 8/7c on The CW! <a href="/hashtag/dcweek?refid=13&__tn__=%2Cg"> <span > #</span><span >DCWeek</span></a>