Towards the end of the Lord of the Rings there is a significant piece of dialogue-
" 'Well here we are, just the four of us that started out together,' said Merry. 'We have left all the rest behind, one after another. It seems almost like a dream that has slowly faded.'
'Not to me,' said Frodo. 'To me it feels more like falling asleep again'."
Each of the hobbits have, physically, travelled long distances but Frodo alone has travelled to places beyond the merely physical. He has had peak experiences of darkness and light and these have taught him that the world we inhabit, so close at hand and seeming solid, is really ephemeral by comparison with what lies beyond the boundaries of normal vision and experience. In that sense he resembles the traveller in the cave allegory of Plato, having seen the Sun he knows that normal life is a focussing on shadows.
More than that, Frodo has been wounded-
'There is no real going back. Though I may come to the Shire, it will not seem the same; for I shall not be the same. I am wounded with knife, sting, and tooth, and a long burden. Where shall I find rest?'
Although his injuries were inflicted with malevolent intent, aiming to subdue him to the rule of evil, they have not been effective. His restlessness does not seek slaves to satisfy itself like a Sauron or a Saruman. No, Frodo’s hopes are set elsewhere-
...the ship went out into the High Sea on into the West, until at last on a night of rain, Frodo smelled a sweet fragrance on the air and heard the sound of singing that came over the water. And then it seemed to him as in his dream in the house of Bombadil, the grey rain-curtain turned all to silver glass and was rolled back, and he beheld white shores and beyond them a far green country under a swift sunrise.
The purpose of Christian mysticism is to seek union with God not to enjoy what classical authors call ‘consolations.’ Nonetheless, for many mystics transcendent moments, glimpses of the Divine do form part of the journey. Those moments of grace have the twofold effect that Frodo experienced, that is they make the mystic see the world differently, as less substantial, and they resemble a wounding. The Catholic mystical writer St John of the Cross put it like this-
Where have you hidden,
Beloved, and left me moaning?
You fled like the stag
after wounding me;
I went out calling you, but you were gone.
Having been wounded the only cure is to seek out the One who inflicted the wound since He alone has the power to heal. This search, though, will often lead through lands of desolation and darkness, akin to the lands Frodo travelled across in his quest.
Why, since you wounded
this heart, don't you heal it?
And why, since you stole it from me,
do you leave it so,
and fail to carry off what you have stolen?
All we can do is travel, the final decision about when or if we shall encounter the One who heals and then be healed is not ours but His. Tolkien indicates this by the way in which he allows providence and not Frodo himself to effect the destruction of the Ring on Mount Doom. Frodo’s time in the Shire, however, is not simply a passive waiting for the final journey. Although he is little seen and less regarded by most of the hobbits of the Shire it is his wisdom and guidance which lies behind the active measures, and the compassion, by which Merry, Pippin and Sam set things to rights. Mystics, contemplatives and hermits are not called to self indulgently seek a private fulfillment but to be witnesses to the world of the deep truth that lies hidden to eyes that do not seek it. Frodo uses his experience, and his wounds, as a guide to those who have travelled less far than him.
One of the concerns of most religions is to help prepare people for death and Frodo’s last few years in the Shire and his final journey into the West can be seen as metaphors for old age (or sickness) and death. But there is no real contradiction between the mystical path of seeking union with God and the more common one of preparing for a good death. The end is the same, to be at rest in the eternal heart of infinite love who is our God. The mystic, like Frodo, experiences here and now a foretaste of what each of those who are faithful to the end can hope to experience forever.
LOTR quotes can be found at http://coco.raceme.org/literature/lordoftherings/returnking/quotes/shire.php
St John of the Cross quotes from