Who? Who Is It?

A blizzard has been going on for ten days, preventing any of the children from leaving the cave. Shingo, Chako and Adam use the opportunity to investigate the card they found in the ruins. They realize the card is a biometric identification system, encoded to respond only to Adam. Bell, Luna, Shingo, Chako and Adam brave the blizzard to head for the ruins. While they stop for the night en route, Adam dreams about his parents. Chako starts shutting down due to the extreme cold, but at her insistence, they press on. They reach the ruins and try to open the door, but Chako collapses. Adam cries out for her, and suddenly the card lifts into the air, glowing green, and the door opens.