I try to outthink my fear. You're over-reacting, I tell myself. Jack, while exhausted, is in no immediate danger. The problem is that a threshold has been crossed. His momentary frailty forces me to confront a different kind of frailty, one not of the moment. Which is that at some point--whether now or in a year or in 25 years--Jack will die. No surprise there. I have days when my own immortality seems doubtful. The surprise is that I'm suddenly aware of how large a hole his passing will leave in my life. Shape up, dumbass. You've got a job here. The next thing I know, I hear myself ordering Jack to hold up a moment. I walk up to him and wordlessly unsling his pack from his back and put it atop my own. I find a suitable stick, break it to staff length against a rock, and put it into Jack's right hand, cupping his fingers around it. I don't look at him as I do these things. I don't know how he's taking them. It doesn't matter how he's taking them. "That stick's a good idea," he says, forcing the tiniest note of cheer into his voice. I'm not sure whether he has actually rallied a bit or is faking it for my bene-fit. I almost don't want to know. I'm still flooded, staggered by my new knowledge. I can barely contain the guerrilla feelings--love, fear, and astonishment at being so split open--that have breached my perimeter. This, I tell myself, is exactly the kind of crap that happens when what you know in your head migrates south into your heart. I'm not the type who makes friends fast or easily. The truth, I realize, is I don't really know how Jack and I became friends. I don't know why he is so important to me. I know that I'm lucky to have him as a friend. At the same time, it hurts. Because I won't always have him.