Midnight Terror

Waking up from a party you had at this abandoned graveyard, your friends are nowhere to be found. What? The main gate is now locked! You could swear it was wide open, when you all entered. Now desperately looking for a way to escape, you keep hearing eeire noises from what seems like every direction. 

Horrified, you suddenly get a chilling realization:

you might not be the only one here...