Charles is a jackass.
He barely knows Sarah, and all she has done is lie to him.
His last word from her is refusal of him.
Yet he rejects Ernestina, to both their profound harms, on a baseless hope that, once Tina is rejected, Sarah will accept him and he and she will be happy ever after.
He eventually finds her, and it appears they are reunited in the end, anyway.
A happy ending.
But not the last.
Reading The French Lieutenant's Woman.