When dissatisfied shopper Marsha White tries to return a purchase to the eighteenth floor of a department store, she is surprised to find out that no such floor exists. Feeling faint, she lies down in the store manager's office and wakes up, hours later, after the store has closed for the night. Wandering the dark and empty store, Marsha hears voices calling her to the eighteenth floor as her unusual shopping trip continues in a very unexpected way.