"It's spring break, and the pretty little liars are trading in Rosewood for a cruise vacation. They want nothing more than to sail into the tropical sunset and leave their troubles behind for one blissful week. But where Emily, Aria, Spencer, and Hanna go, A goes, too. From scuba diving to tanning on the upper deck, A is there, soaking up all their new secrets. Emily is smooching a stowaway. Aria's treasure-hunting partner is a little too interested...

Sylvie Bates-McAllister finds her life upended by a late-night phone call from the headmaster of the prestigious private school where her adopted son Scott teaches. Allegations of Scott's involvement in a hazing scandal cause a ripple effect, throwing the entire family into chaos. For Charles, Sylvie's biological son, it dredges up a ghost from the past who is suddenly painfully present.

"It's springtime in Rosewood, but while everyone else is searching for the perfect prom dress, Hanna, Spencer, Emily, and Aria are on a different kind of hunt: They're looking for A...Hanna puts her campaign for prom queen on the back burner to volunteer at a burn clinic, where one of A's victims is recovering. Emily digs into Ali's past at the mental hospital with some very crazy consequences. Spencer contacts an amateur private eye to help her stalk...

Former best friends Emily, Aria, Hanna, and Spencer continue to live in fear as they struggle to keep hidden even more secrets and someone new begins stalking them via their cell phones.

When one of their tightly-knit group mysteriously disappears, four high school girls find their friendship difficult to maintain when they begin receiving taunting messages from someone who seems to know everything about their past and present secrets.

Poppy, Aster, Corrine, Natasha, and Rowan are the heiresses of the Saybrook's jewellery empire, a family business that is known for both its wealth, and a very old curse that leads to family members dying suddenly. When one of the 5 heiresses is killed, and an online gossip site publishes a statement "One Heiress Down, 4 more to go", an investigation is opened.

Aria's love life is on the Fitz--ahem, fritz. Emily's exploring her wild side. Hanna's kissing the enemy. And someone from Spencer's past--someone she never thought she'd see again--is back to haunt her. But none of that compares to what these pretty little liars did on their last spring break. It's their darkest secret yet. And guess who else knows?

High school seniors Aria, Emily, Hanna, and Spencer have all done horrible things -- things that would put them behind bars if anyone ever found out. And their stalker 'A' knows everything. So far A has kept their secrets, using them to torture the girls. But now A's changed the game. Suddenly the girls are hauled in for questioning, and all their worlds begin to unravel. If A's plan succeeds, Rosewood's pretty little liars will be locked away for...

Now seniors in high school, Spencer, Emily, Hanna, and Aria's friendship has been torn apart by new lies and stress, but they are drawn back together when anonymous messages threatening to reveal their secrets resume.