Today is Sophie Matthews's sixteenth birthday party, an exclusive black-tie bash. Sophie's dad has spared no expense, and his cliffside mansion - once thought haunted and shuttered for years - is hosting the event. Then, just before the candles on the three-tiered red velvet cake are blown out, a body falls from the balcony onto the dance floor below. It's a killer guest list ... Dani: Sophie's new stepmother who's plagued by self-doubt. Orlaith: the nanny who senses danger. Mikayla: the best friend who is not nearly as meek as the popular kids assume. Kim: the ex-wife who has a grudge she can't let go of. Everyone is invited in. Not everyone will get out alive.