Luther's answered this question before from Allison, and so he's accustomed enough to deliver the tame and toothless summary that doesn't actually touch on any of the heart of it: "It's pretty different. Bigger, for one."

But then Klaus' words thoughtlessly roll on like a bubbling brook, and Luther record-scratches to a halt. Glances over to his brother, with his brow furrowed in confusion, as that sentence simply doesn't track. "In the war?" he asks. "You mean, our training?"

Because their childhood was a war — but for some reason, he doesn't think that's what Klaus is referring to.