A hospital's graveyard shift is chaotic on a "normal" day. Irritable, irrational people abound - and then there are the patients Danni Parker has managed to survive this mayhem for the past year; working as an Ultrasound Technologist. The nights of challenging patients are longer than the sleepless days but with the help of her friend, a sassy Cuban American nurse named Mercedes Perez, she finds a way to have fun living a singles life in South Florida. One night, between bouncing from one patient to the next, Danni makes the fateful decision to climb the stairs to the third floor where she over hears a conversation that turns her world upside down. Two men, one of whom Danni thinks she recognizes, are discussing the murder of a playboy millionaire. Narrowly escaping detection; Danni now has to convince the authorities that what she heard was real and that she can identify one of the perpetrators. Unable to persuade the handsome police officer Leo Flynn, Danni must somehow find proof. With the help - or in spite of - her friends, Danni must act before the murderers get away. Or worse yet, they could decide she is next