"A mile," Russell mutters, burying his face in a hand. How Benjiro could calculate the scale is beyond what he can grasp right now, but the sense of that distance in the tunnels is considerable.

"Alone, a mile away. Climbing, without any way to contact anyone." He shakes his head slowly, letting out a breath in less of a hiss than a shudder. "That's... I thought I should stay back. We shouldn't have let you stay back alone."