Fraternal twin sisters, Fern and Rose, look nothing alike yet they are devoted to each other. Rose takes care of Fern whose autism spectrum disorder often leads to sensory overload.

The two of them have had a difficult childhood — their mother has not always provided a stable home. They emerge mostly unscathed except for that one time Fern did a horrible thing during a camping trip. At least, that is what Fern has always believed.

As fully grown adults, both now have jobs–Fern works in a library and Rose has a corporate job, yet they are curiously dependent on one another.

When Fern learns that Rose and her husband cannot conceive a child, Fern decides to give one to Rose. She decides to have a baby with a stranger (in this case Wally) in order to pay Rose back. While her intentions are pure, Fern does not realize her thinking is illogical.

Since this is a Hepworth novel, there is more going on here than meets the eye. Fern frequently forgets things and misunderstands social norms. She may have even have accidently drowned a boy. Can she possibly be trusted with a child?

This a taut psychological novel about the close bond sisters share and the sacrifices they are willing to make for each other.

The Good Sister won the 2021 Adult Crime Novel Davitt Award.