All That's Left to Say - Emery Lord

Hannah MacLaren has grown up between two worlds: scraping by happily with her single, working mum and avoiding the Maryland upper crust in the next town over, where her wealthy cousin and best friend Sophie lives. The plan is to get out: Hannah from paycheck-to-paycheck life, and Sophie from the cosseted world she doesn't fit into. But just before junior year begins, something goes horribly wrong. Sophie overdoses at a party, leaving behind a shocked community and bereft best friends. As the haze of grief begins to clear, Hannah teams up with Sophie's other best friend, Gabi, to find out what happened that fateful night. Someone gave Sophie oxycodone. Someone knew what was going on. And Hannah will not stop until she has uncovered the truth.