I received this as a Goodreads Giveaway.
Whole tells the story of a young 20-something named Mara who runs her own cake business and lives with her boyfriend Jake. One day on a run with Jake, she trips off of a city curb and finds herself in a desert, Jake yelling at her to keep running and men in tuxedos trying to capture her. A portal opens up and brings her back to Chicago, but she is intrigued, running the same route the next day to see if she can figure out what happened. As it turns out, she has a connection to Pearth, an alternate universe where she reconnects to her dead father and a more serious version of her boyfriend (thanks to the other reviewer who pointed out that "Pearth" is likely a portmanteau of Parallel Earth). She learns she is one of several individuals who can save Earth by destroying the rings that allow them to travel between universes.
I feel like that is an unclear and incomplete synopsis of the story because I honestly got very confused. I thought I was following along, but as it went on, I felt more lost. I don't know if there were inconsistencies in the story, or it is simply my lack of understanding that led to my confusion. For instance, I thought when Mara initially arrived on Pearth, she was told when she was there, time on Earth just kind of didn't change, which made sense to me to explain how she disappeared for a hot second on her long run with Jake and then reappeared without him questioning what happened. Yet when she is sent on a mission, she is told to be prepared for a month away from home. Also, I thought when she portalled to Pearth, she would always in her home and when she portalled to Earth, she would always arrive at some base location (for some reason hers was an alley with rats who gathered and bowed at her at the end of the book, I kid you not). Yet she was able to leave Earth in France, arrive to her traveling companion's house, and then return back to Earth. Then she had to take a plane back to Chicago... could she not just have portalled to Pearth and then back to Earth to arrive to her rat-infested alley? I don't know. This was either poorly explain inter-universe travel or it is just beyond my understanding.