The Soul Reader

Everyone in the world has a partner out there to search for and now they're easier than ever to find with The Soul Reader.
The Soul Reader is a wonderful invention that taps into your body and mind and, of course, helps you find your soulmate. When first created, This Reader was just a funny little machine solely for entertainment purposes. 500 years later, it's been integrated into the very system that runs this world.
There are some rules though, mainly, it is illegal to marry a partner that is not your own. Possession of another's soulmate is a serious criminal offense but that hasn't happened in hundreds of years. In fact, it's practically unheard of in this day and age.
So what happens to Kayleen when she discovers her beloved husband shouldn't be her husband at all?