We reached the first safe room. During the next area we quit the game. Coming back, there is no option to access the saved campaign. Where is it?
In both the L4D games, there's not a "campaign save" per se. Every time you enter a safe room, that's considered the end of one game, and another starts when you leave it to move on. If you quit without having reached the next safehouse, you'll have to start over from the last safehouse.
If you've quit the game, you can resume from any safehouse, though:
- Select "Play Campaign" from the main menu
- Choose your lobby type (if you're playing split screen, "Play with Friends" is probably appropriate)
- Create a new lobby (press X)
- Choose the campaign you were on and what difficulty you want to play on
- Press "Create Lobby"
- Choose "Edit Game Settings"
- Change the Chapter to whichever chapter you left off on (ie, if you were playing Dead Center and got to the first safe room, you probably want to start on "2: Streets")
- Start the game