"Not today," he deadpans, meaning it to be a joke, but Isaac feels like maybe some of it got lost in translation. "Actually, no, it's not..." He glances around them, making sure that no one's about to attack while Isaac talks about his pet theory. "I'm kind of curious about what happens in these doors. I mean, which is reality? And how do you test reality? I mean, the best and worst way I can think of is dying," he says with a fluid shrug -- practiced and perfected by teenage boys everywhere. "If you die here, do you die at home? Will you never go back?"