The Space Between Worlds takes place on an Earth utterly unlike our own and yet so eerily similar that I can conceptualize it with crystal clarity. That said, the world(s) our protagonist — who I will call Cara — walk through are ones that I would shudder to find myself within, and I count myself incredibly lucky to not stand inside her shoes.
The premise of The Space Between Worlds is insidious in its simplicity; traveling between realities is entirely possible, but only if the version of yourself that exists in the alternate reality has died. As elegant as it is terrible, the natural result is that the superpower our main character is endowed with is that she stays alive while hundreds of other hers die over and over in a myriad of ways. The dead weigh on her, her other selves articulated as a sensation that is never established as being spiritual or scientific but is nevertheless tangible. Cara is a traverser — it is her job to travel to other worlds and bring back information about those worlds to Earth Zero. She is uniquely equipped for this position because no one else is dead in as many other worlds as she.
There are so many things I love about this book — many of them spoilers — but one that is an automatic win for me in any media is unapologetic queerness, which The Space Between Worlds has in spades. Cara sits comfortably in her bisexual identity. At times hesitates in mentioning her sexuality in front of those that she knows might disapprove of her feelings toward women when it threatens safety or precious relationships, but she nevertheless lives her life as she is wont and pursues who she likes regardless of the opinions of others.
I do not want to say much more about the plot because I do not want to spoil any of the delightful thrills that come with experiencing The Space Between Worlds for oneself, but I will say that I found it to be a thoroughly enjoyable read overall. My only notes of caution are that some parts of the book are incredibly violent, and parts of it may be difficult for those who are survivors of domestic abuse. That said, if those are not triggers that would prevent you from enjoying the book, I highly recommend you put The Space Between Worlds on the top of your to-read list.