Girls Across Worlds - Ranger Paraversum, #4

How do you find someone when you don't know who they even are? It's early 1946, the Cartographer chapter of the City of Rijeka is in turmoil, and the worlds of the known paraversum are under threat. As members of the Cartographer Association-literally, the people keeping the access points between the worlds secret-Lina and her otherworldly doppelgänger Karol would be involved with trying to stop the first inter-world conflict either way.
But, with their private arrangement finally out of the basement-and the consequences of breaking the Cartographer rules hanging over the lovers' heads-it's almost impossible for them to avoid getting dragged right into the storm. As their bosses combine their resources to stop the elusive, mysterious chapter that's taking out others one by one, the girls find themselves at the forefront of a clandestine task force setting out across the worlds in search of the one person who might put a stop to it all-if only they manage to find out who they even are.
Only, this time, they're supposed to be working with other Cartographers-not solving another puzzle with just the two of them, as they've grown accustomed to. And not everybody has the paraversum's best interests in mind. Girls Across Worlds is the fourth book in the retrofuturistic mystery series Ranger Paraversum. Start with book one: Johnny's Girls.