Two free tickets, can't get any better than that!
At home, you misplace your tickets someplace and only could find one. That's ok, it wasn't like you were going in a group or anything. The best time to go would either be in the morning or night to beat the crowds, and you decide it would be best at nightfall.
You did manage to get to the zoo, but since the roads were packed, it was close to closing time. "I drove all the way out here and I'm not leaving until I see some attractions!" you say aloud. You hand the lady your ticket and walk in.
It looks like any other normal zoo, so what's so special about it? There's hardly any people around, this starts to get you a bit nervous. "Maybe they're someplace else," you say until the answer dawns on you. The lights go out in the zoo. "Oh no." You run back to the entrance to find it locked tight, and there's no way you can climb the gates with nothing to grab onto. Just great, your day off and you're locked in...a zoo. You can either explore the place for the fun of it, or find some way to get out.