I read Tandem as it was on a recommendation list for books similar to These Broken Stars.
Sasha, a mundane, modern-day Chicagoan, is hoodwinked by secret agent Thomas and whisked away to Aurora. Aurora is a parallel world that greatly resembles Earth…except for the fact that the Aurora Borealis can be seen everywhere, every night, and the fact that North America is divided by the Mississippi into two kingdoms. Instead of a united country, the United Commonwealth of Columbia and Farnham have been embroiled in bitter war for centuries. It is hoped that an arranged marriage between each kingdom’s heir will unite everyone and put an end to the bloodshed. Continue reading