Zula had been noticing that Chet’s condition improved markedly when something happened to trigger an adrenaline surge and declined during uneventful parts of the journey. At the moment he seemed quite energetic, so she was surprised that he was now requesting a break; but perhaps this was just his polite way of saying that he wanted her to leave him alone so that he could take a leak. Certainly he had been drinking enough water. So she walked up the adit to the second hole on the left and smelled and saw more graffiti. But she smelled something else as well: a current of fresh air coming down from that direction.