Burning September by Melissa Simonson

Kat’s life is going exactly the way her sister has planned it, until a detective shows up at their front door early one morning and arrests Caroline for murder.

Suddenly and utterly alone, Kat doesn’t know how to navigate a world without Caroline, the woman who raised her. During the aftermath of the crime, Kat tries to figure out who she is without her sister, but unlocking those doors only leads to more troubling questions.

Kat realizes the one person she thought would never lie to her had, and quite frequently. Sorting through the skeletons and lies might be more than she can handle, but it’s a necessary evil if she ever wants to see her sister acquitted.