When a Russian government minister is found dead in his cabin aboard the imperial yacht Standart, his death is shrouded in mystery. But the tsar's eldest daughter, Olga Romanov, suspects foul play and enlists her sisters — Tatiana, Maria, and Anastasia — to solve what she suspects to be a case of murder. Layers of mystery and intrigue unfold as each sister plays a part in this chilling adventure that culminates with Olga uncovering the shocking truth and racing to stop the killer from striking again.