Where the Cold Forks

You came down into the Veldrun Caverns three hours ago looking for your missing sister, Senne. Near the great fork where the southern passage splits into the upper galleries and the deep river-run, you found her lantern frozen solid in a block of pale ice on the cave floor — still lit, flame suspended like an amber bead inside the glass. Beside it, slumped against the wall with his back to the cold stone, sits an old guide named Corvel who says he has been here since morning, too stiff to move, too proud to shout for help. Two tunnels yawn ahead of you; a makeshift camp surrounds the ice block. You don't know which way Senne went.