"the far side of trouble"

In the second to last chapter, Inman allows himself to feel that he can be healed---both physically and, more importantly, spiritually.  Part of it comes from simply be able to talk with Ada.  At first she asks about the war and the "great celebrated warriors" he might have seen.  But he doesn't want to talk about it.

     ---Then tell me of your long journey home, Ada said.
     Inman thought about it, but then he let himself imagine he had at last come on the far side of trouble and had no wish to revisit it, so he told only how along the way he watched the nights of the moon and counted them out to twenty-eight and then started over. . . . But how on the best days of walking he achieved some success in matching his thoughts to the weather, dark or bright, so as to attune with what freak of God's mind sent cloud or shine. 

So in a way, he has become more "attuned" to Nature, just as Ada has. Though his is a darker vision as indicated by the phrase "freak of God's mind."  In war, what Inman has experienced is the arbitrariness of it all.

In his experience, great wounds sometimes healed, small sometimes festered. Any wound might heal on the skin side but keep on burrowing inward to a man's core until it ate him up. The why of it, like much in life, offered little access.

Ada's lessons, on the other hand, have been primarily positive ones.  When Inman says, "I'm ruined beyond repair, is what I fear," Ada provides him with her new insights, which are variation on Ruby's perspective.

What she [Ada] thought was that cures of all sorts exist in the natural world. . . . And there was spirit rising from within to knit sturdy scar over the backsides of wounds. Either way, though, you had to work at it, and they'd both fail you if doubted them too much. She had gathered that from Ruby, at least. 

This chapter is a leisurely one.  Basically, we have two wounded men being taken care of by strong women.  The strength of the bond between Ada and Ruby is also emphasized to the point of almost becoming a marriage.  When Ruby tells Ada that they don't need Inman, that "We're just starting. I've got a vision in my mind of how that cove needs to be," here's Ada response:

She took one of her rings and put in on Ruby's hand and tipped it down to the firelight to look at it . . . Ada made motions to leave the ring where she had put it, but Ruby took it off and twisted it roughly back on Ada's finger.

There is the healing consummation of sex too, but Frazier is discrete and tender with it.

      He [Inman] bowed his forehead to the soft of her stomach. Then he kissed her there and she smelled like hickory smoke. He pulled her against him and held her and held her. She put a hand on the back of his neck and pulled him harder, and then she pressed her white arm around him as if forever.
      With the snow piling up outside, the warm dry cabin hidden in its fold of the mountain felt like a safe haven indeed, though it had not been such for the people who had lived there. Soldiers had found them and made the cabin trailhead to a path of exile, loss, and death. But for a while that night, it was a place that held within its walls no pain nor even a vague memory collection of pain. 

At the point of intimacy, Frazier pulls back and gives us a larger view.  For Ada and Inman the cabin was a "safe haven," but the narrator knows it's only a temporary condition. The very cabin which is a save haven for Ada and Inman was a "trailhead to a path of exile, loss and death" for the Indians who had built it.

And for a moment, we hearken back to the story Inman told before he left, the story about the Indian tribe who had been granted a vision of wonderful valley but lost their chance to enter it because one man among them disobeyed the commands and as a result infected everyone else with fear. And that fear kept them from being able to enter their Eden.