My life has never been better. I have a beautiful little girl, and I am engaged to be married to the man I’ve had a crush on since I can remember. So when Nick, my handsome fiancé, announces that his sister Carla is finally coming home, it’s truly the icing on the cake. That was twelve years ago, and no one has seen her since. Everyone is ecstatic about Carla’s return. But as I spend more time with her, I can't shake the feeling that something isn't right. Her behavior is a little off, her childhood memories don't align with mine, and she's oddly evasive about her lost years.

Amy is trapped in a nightmare with Jason, a controlling, violent husband. Then on a short cruise without him, Amy befriends Liz, a young woman traveling alone on her way to meet her birth mother for the first time. Liz looks so much like Amy that they could be sisters. When Amy regains consciousness after a terrible accident that takes the lives of many passengers, she finds that, because of a mix-up in personal effects, everyone believes she is Liz. Only she knows it is Liz who has gone missing, presumed dead.

There are only three things in this world that are certain: death, taxes, and babies. Nobody knows this truth better than Emily McCoy, a third year resident working in Baby City, the affectionate nickname for the busy Labor and Delivery unit at a New York City hospital. On a typical day in Baby City, Emily delivers more babies than the number of hours of sleep she manages to squeeze in that night. And definitely more than the number of dates she's been on since she started her training in OB/GYN two years earlier.

Medical student Amy Brenner is spending the night on a locked psychiatric ward. Amy has been dreading her evening working on Ward D, the hospital’s inpatient mental health unit. There are very specific reasons why she never wanted to do this required overnight rotation. Reasons nobody can ever find out. And as the hours tick by, Amy grows increasingly convinced something terrible is happening within these tightly secured walls.

Blake Porter is riding high, until he's not. Fired abruptly from his job as a VP of marketing and unable to make the mortgage payments on the new brownstone he shares with his fiancée, he's desperate to make ends meet. Enter Whitney. Beautiful, charming, down-to-earth, and looking for a room to rent. She's exactly what Blake's looking for. Or is she? Because something isn't quite right. The neighbors start treating Blake differently. The smell of decay permeates his home, no matter how hard he scrubs. Strange noises jar him awake in the middle of the night.

Amanda is a hardworking single mum, completely focused on her job and her daughter, Louise. She’s been saving for years, and now, finally, she can afford to give up work and chase her dream. But then, on her commute home from London to Brighton, she meets a charming stranger - who seems to know everything about her. He delivers an ultimatum. She needs to give him the code for the safe where she keeps her savings before the train reaches Brighton - or she’ll never see Louise again.

Cassie thinks she has met the perfect man. Joel is sweet, handsome, romantic, and best of all, he’s crazy about Cassie. She thinks she’s found the guy she’ll spend the rest of her life with. Have children with. Grow old with. Yes, she knows about his perfect ex-girlfriend, Francesca. The beautiful, brilliant chef, beloved by all his friends. But she thinks Francesca is out of the picture. She thinks Francesca is gone for good. Think again, Cassie.

When Heather McKinley dreamed of becoming a doctor, she imagined curing sick kids and sporting pink stethoscopes. She never anticipated the sleepless nights, grueling exams, and endless labs. And she certainly never knew that her medical school earned the nickname Dead Med thanks to the tragic history of students overdosing on illegal drugs. But Heather would never consider doing anything like that. That is, until her longtime boyfriend dumps her, she finds herself failing anatomy, and her world starts to crumble.

Lucas knows the perfect night entails just three things: video games, wine, and pad thai. Peanuts are a must! Other people? Not so much. Why complicate things when he’s happy alone? Then one day the apartment board, a vexing trio of authority, rings his doorbell. And Lucas’s solitude takes a startling hike. They demand to see his frying pan. Someone left one next to the recycling room overnight, and instead of removing the errant object, as Lucas suggests, they insist on finding the guilty party. But their plan backfires. Colossally.

Tess Strebel can’t recognize her own face. She can’t recognize her home. Her bedroom is unfamiliar. And she can’t remember the handsome stranger lying next to her in bed. A stranger who claims he’s her husband. Tess reads a letter in her own handwriting, composed during a rare lucid day, explaining her life as it now exists: she was in a terrible car accident one year ago. Every morning, she wakes up unable to remember most of the last decade. Including her own wedding.