Thea Luckmore believes in love - the magic spark of true, old-fashioned, romantic love. She's determined only ever to fall head over heels, or rather, heart over head. Alice Heggarty, her best friend, is always falling in lust - with dashing rogues who invariably break her heart. As yet another disastrous relationship ends, Alice makes a decision. It's time to marry and she knows just the man. For Thea, Saul Mundy promises to be the perfect fit and Thea finds herself falling in love and loving it. But though newly wed Alice encourages Thea to settle down and conform, she finds that she's not as keen as she thought on playing by the rules. Alice starts to break them left, right and centre - At the same time, Thea's world, in which love reigns supreme, is shaken to core.