The Left Hand of Darkness by Ursula K. Le Guin

'Love doesn't just sit there, like a stone, it has to be made, like bread; remade all the time, made new'
 
Two people, until recently strangers, find themselves on a long, tortuous and dangerous journey across the ice. One is an outcast, forced to leave his beloved homeland; the other is fleeing from a different kind of persecution. What they have in common is curiosity, about others and themselves, and an almost unshakeable belief that the world can be a better place.

As they journey for over 800 miles, across the harshest, most inhospitable landscape, they discover the true meaning of friendship, and of love.