Several people from hell climb aboard a bus destined for the valley of the shadow of life. It is the land on the fringes of heaven. All who want to stay and go further up into heaven can. The solid people of heaven (mostly relatives and former friends of the travellers) come down from the mountains to invite them in. The shock of the book, is that in the end, very few choose to stay. These travellers view the fringes of heaven, as a damnable place. Their ever shrinking, translucent, slowly disappearing bodies don't like the light and the grass is much to hard to walk on, heaven can only be worse they think.
Make no mistake, the inhabitants of hell are absolutely miserable and getting more so every day. There is no peace in hell, only fights and separation, darkness and loneliness, but they cling on to their misery. You see, all the inhabitants of hell are self absorbed. They are the centre of their own ever shrinking, ever disappearing, ever solitary universe -- but in the end, they want themselves more than joy itself. When confronted, they lash out, blaming others for the fix they are in. Some are interested in God, but only as a means to an end, God is a useful tool to better ones on reputation, or to gain someone or something. For others heaven is seen as a place to become a shining star, in every case, when the people of hell realize that they can't get what they want out of God and heaven, they become disgusted with it. Disgust for the heavenly spirits grows even more when the ghosts of hell realize the earthly failings of some of the heavenly people they get re-aquainted with. Self righteous hatred tries to spew itself on the people of heaven, but darkness cannot over take the light of heaven, not even on it's fringes, so instead there is only laughter, light, joy, and the call for the ghosts to repent and start up the mountain where they will experience painful but purifying cleansing. They won't have it, back to the bus they go.
Many religious people find themselves in the town called hell in this book. Lewis offers a poignant warning:
"There have been men before now who got so interested in proving the existence of God that they came to care nothing for God himself...There have been some who were so occupied in spreading Christianity that they never gave a thought to Christ... it is the subtlest of all the snares'"
When self-exaltation is the driving force of ones life, when "me" is at the centre, it doesn't matter whether the life pursuit is noble or not, heaven and eternal joy itself will actually become inhospitable and undesirable.
Lewis' ability to capture the true darkness of a human heart, is quite unsettling. The hell in all of us is revealed with convicting accuracy. The foolish choices we make in order to hang on to ourselves, at the expense of true joy hit really close to home for the honest reader.