Charlie Saxe grew up in the seedy underbelly of Umbra before she was adopted and allowed to live in the palace. Since then, she has been training for years to be able to infiltrate an Equivalent high school, a task she needs to succeed at in order to make her adoptive father proud. Everyone in her world knows about the existence of the parallel universe Equivalent, but only trained soldiers are allowed to go there. After all her hard work, she refuses to let anything get in her way, including the inappropriate crush she happens to have on her target, Kav Kavanaugh. However, when the only thing she can do to keep him safe is illegally sneak him into her world, Charlie is forced to put her personal needs aside. Counterpart is run by a monarchy, and she and Kav must help her King uncover a mole within the palace before Kav can return home. As the two of them grow closer, Charlie makes contact with the boy she left behind in Umbra, and discovers a conspiracy theory against the king that could change everything she thought she knew and believed in.

Charlie Saxe's entire world has been turned upside down. The return of the rightful heir to the throne has thrown everything into disarray, including Charlie's relationships with the people around her. The palace is divided, some standing with the old king, while others fall in line with the crown prince. Charlie is expected to be a part of the latter group, and her hesitation to do so could end up resulting in the death or imprisonment of the people she cares about. Kav Kavanaugh is forced on the run. Again. Only this time, he needs to fight for Charlie instead of with her. He refuses to give up on everything they'd shared and is unwilling to leave her behind, even if that might be the safest option left available to him. Ace has plans of his own, plans that have been years in the making. Determined to win, he holds fast to his newly taken power and all the things that come with it. Including Charlie. He wants to rekindle what they once had, even if that means burning everything else to the ground. Torn between her newfound love for Kav, and the old loyalty she once felt for her childhood friend, Charlie is forced to make a decision. Stay and fight for what she believes is right, or find a way to escape back to Kav's universe before it's too late?