The Chink in the Armour by Marie Belloc Lowndes

And then there began a series of long cloudless days for Sylvia Bailey. For the first time she felt as if she was seeing life, and such seeing was very pleasant to her.

Not in her wildest dreams, during the placid days of her girlhood and brief married life, had she conceived of so interesting and so exhilarating an existence as that which she was now leading! And this was perhaps owing in a measure to the fact that there is, if one may so express it, a spice of naughtiness in life as led at Lacville.