Beware of Pity, by Stefan Zweig
In 1913, a young Austrian officer visits a wealthy man's home. During the evening's entertainment, he accidentally makes a faux pas by asking the host's pretty young daughter to dance, not realizing that she lost the use of her legs in an illness. His efforts to make up for hurting her feelings draw him further into the family, but he is unequipped to cope with their desperation for healing and the emotional blackmail they exert upon him. Although he loves them, he cannot fix them, but he also can't refrain from trying.
I really enjoyed this novel, which I took quite slowly--and that was a good thing.