Or it could mean that they're dead. Julia doesn't want to say it but it's true.

You know it. In your bones, you know it. Had Joker seen no Batman was coming for him up there, he would have known....

Now, now you just have to find the damn stuff. The evidence is there, you got your look at the Owls' model... they mined not far away. Still, the caverns are a maze.