Albert quickly makes his way through the complex, faster than he could have if the people filling the halls were actually moving. He's at the entrance to the main stage before he consciously realised that's the direction he was headed.  
Initially he doesn't see anything different, just more frozen people, mostly staring at the stage itself. But as he turns to wander elsewhere, another of his new friends spoke up in his head.  
[color=0076a3]"Not so fast, remember what I said before, when you encounter a coincidence or wander somewhere seemingly by chance, that's not chance, that's the force sticking its nose into your life, and it's probably best to roll with it. Let it guide us, I think the stage is why we're here."[/color] 
Albert hadn't had company in his head for long, but they'd yet to steer him wrong, possibly because they are him? Point is that he did as suggested, approaching the stage, at which point he notices the drops of blood, and isn't it weird that he doesn't even entertain the notion it's anything else, and more importantly the fact that the people lying on stage were not actually frozen, their chests moving slightly as they breathed.