The girl who lied

Erin and Roisin were once friends until a fatal accident ruined both their lives. Now, Roisin has discovered a secret--one Erin has kept for over a decade--and she's determined to make Erin pay for her lies.
When Roisin suddenly disappears, suspicion soon lands on Erin. She would do anything to protect her family, but just how far is she willing to go when time is running out? [From back cover.