Despite being the youngest partner at her firm, corporate attorney Davy Dugan is gunning for a recently vacant name partnership--it would mean finally having the power to make a real change in her conservative workplace. But eighty-hour workweeks don't allow any time with her much younger half-sister, Tally, who doesn't seem to need Davy in her life anyway. Davy aims to get back into Tally's good graces by throwing her a big birthday party, but that means dealing with Tally's other half sister, Anna. To say Davy and Anna don't get along is putting it mildly. When a misunderstanding leads to her boss's assumption that she and Anna are headed to the altar, Davy sees a way to leapfrog over the competition straight into one of the top spots at her firm. She just has to convince Anna to be her faux fiancée in order to do it and keep her growing attraction in check, of course.