When a handsome stranger in a coffee shop asks her to watch his laptop for a moment, Fixie Farr not only agrees - she ends up saving it from certain disaster. It turns out the computer's owner is an investment manager. Sebastian scribbles an IOU on a coffee sleeve and attaches his business card. A new series of IOUs between Seb and Fixie - from small favours to life-changing moments - ensues. Soon Fixie is torn between her family and the life she really wants.