The Other Daughter by Lisa Gardner

From the #1 New York Times bestselling author of Before She Disappeared comes a propulsive thriller exploring “the dark side of family life, where the ties that bind also gag, choke, and strangle” (Publishers Weekly).
 
“Lisa Gardner always delivers heart-stopping suspense.”—Harlan Coben
 
The family you love the most may be the people you should trust the least. . . .
 
Twenty years ago, Melanie Stokes was abandoned in a Boston hospital, then adopted by a wealthy young couple. Gifted with loving parents, a doting brother, and an indulgent uncle, Melanie has always considered herself lucky. Until tonight.
 
Tonight, a has-been reporter turns up, investigating her past. Tonight, the first note arrives, saying, “You Get What You Deserve.” And tonight, Melanie has her first, horrifying vision of the past.
 
Melanie has no memory of her life before the adoption. Now someone wants to give it back, even if it includes the darkest nightmare the Stokes family ever faced: the murder of their first daughter in Texas. As Melanie pursues every lead, chases every shadow in search of her real identity, two seemingly unrelated events from her past will come together in a dangerous explosion of truth.
 
Winner of the Daphne Du Maurier Award for Suspense.