Break Us by Jennifer Brown (Nikki Kill #3)
Nikki Kill doesn’t see the world in black and white. Her synesthesia shades everything in view, transforming numbers, words, and emotions into colorful clues. Which means she’s a dangerous commodity to anyone with something to hide. Nikki has already taken on the Hollises–one of L.A.’s most powerful families–for murdering her half sister, Peyton. However, Nikki’s next steps are clouded by the gray of uncertainty. Before she knows it, Nikki is on the trail of a cold case that couldn’t be any more personal–the death of her mother. But when the web of lies and secrets she uncovers leads back to the people who have tried to silence her, Nikki must pursue the sunbeam gold of justice, or everything–including her life–will be lost.