This special black-and-white episode gives a nod to 1940s-era film noir as Spencer's numerous sleepless nights with the help of prescription pills start to take a toll on her.

Mona's friend comes to town to pay her respects.

While new discoveries are made in the investigation of Charlotte's murder, the truth begins to emerge about the Liars' personal lives. Spencer is concerned to learn her mother is keeping a secret of her own. Aria confesses to Liam how deeply she's involved with Ezra's book. Ali admits that she and Elliott are more than just friends. Mona reveals where her true allegiances lie. Caleb, Spencer and Hanna deal with the complications of new relationships.

Meanwhile, Emily and Hanna each receive shocking threats that elevate the seriousness of the situation.

Convinced they know who A.D. is, the Liars gear up for a confrontation. Spencer, Hanna, and Caleb team up to investigate and discover new information about Charlotte’s death. Meanwhile, Mary Drake returns with a gift for Spencer and Alison.