I think we've all seen our fair share of 'other women' novels where the rival included is the mistress or vice versa, but trust me when I say that this one will be quite a different twist on that trope. It's clear by the second chapter that something other than the typical is going on here, and it's likely that readers will form their theories as they go along - I won't state my theory for sake of spoilers. I can't wait to see how this one pans out!