With a fantastic attention to detail, the game also leaves clues for the determined player, such as audio logs from dead citizens of Rapture. In the final section of the demo we're shown a record store with the knowledge that a particular musician we need to flush out of hiding has an obsessive hatred for a rival. Once in possession of that recording, viola - one crazed composer literally faces the music.

And with that, the demo session ended, leaving attendees slack-jawed and wanting more. Whether Irrational can deliver on the obvious promise on show here is something we'll find out in time, but for now what we've seen so far has ensured we'll be paying full attention from now on.