Scenario 1:
You wake up to find that you're cold and confused. What... what happened? And who are these strangers?

Scenario 2:
Same as above, but you wake up in a city instead. And you four are the only people in it.

Scenario 3:
You wake up with three others in the dying word of 2119, the last thing you remember is going to bed in your house in 2019.