This was first published in 1873, after his most famous works, and one is tempted to believe that he was trying to use his success and popularity to bring a topic close to his heart to a general audience: the cruel way in which Victorian society ostracises women who have strayed from the path of virtue. In order to make the topic palatable to his audience, he clads the story in cloying sentimentality, showing a persecuted beauty of incredibly pious and submissive humility.
The surprise is that he gives his heroine a happy ending with the preacher who has fallen in love with her. This choice of hero allows him to vent his anger at the double standards and the bigotry of society, who claim to be Christian and yet fail at the most important virtues, namely compassion and forgiveness. He also manages to work in some subtle swipes at the organised charity funded by subscriptions, who mostly fail to reach their intended target because they have no way of learning about these charitable efforts.
Collins has very good insight into how people’s minds work; even if their actions annoy us, they are understandable. Still, it takes a lot of willpower to read through the sighs, tears and self-denials. ( )

Henry James thought Wilkie Collins a sensationalist I found nothing sensational about this novel. A very good read though. ( )

A fairly conventional offering from Collins, with a predictable plot and mostly razor-thin characters. Enjoyable for its flaunting of expected notions of propriety and standards of Victorian womanhood. It's not really a sensationalist novel in the same way many of his other, more extreme books are, but it does include a case of mistaken/switched identity, which you find out about almost as soon as the book opens. Mercy is a bit of a goody two-shoes, but still a likable heroine who was worth cheering for.
Slight spoiler, I guess: leave it to Collins, who lived openly with a mistress for many years, to grant a "loose" woman a happy ending--he's one of the few who would dare to do it (other than female authors, and even then, not many would approach it) during the restrictive nineteenth century. Points for that, even if the ending is somewhat unlikely! ( )