The Left Hand of Darkness: Ursula K Le Guin

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. Winner of both the Hugo and Nebula Awards on its first publication in 1969.