Even when you know it's wrong . . .
'Secrets. She hated secrets. Even the nice kind bothered her . . .'
Karen doesn't want to get mixed up with Zoe at all, let alone listen to Zoe's shocking secret - that Zoe is pregnant! Then, some months later, a baby is found abandoned and Zoe suddenly claims that her previous confession had been made up. Karen is devastated. For Zoe's actions force her to examine her own thoughts about her own traumatic past (she, too, was found as a baby, abandoned, and is now adopted).
When Karen realises what she must do, she finds it's a step into the spotlight - for Zoe, unlike Karen, really can't keep a secret . . .