Elle Bennett and Cassie Reed have been inseparable since the day they were born. Bound by friendship, family, shared memories, and many rules - but there’s one rule that mattered more than all the others: your best friend’s brother is off-limits.For years, keeping that promise was easy - especially when Noah treated Elle like a little sister, and she, her big brother. During his final year and her 10th grade at Brookridge High School, something shifts, and what begins as quiet and confusing soon turns into something neither of them can deny.Breaking this one rule could cost Elle not just her first love, but the most important friendship she has ever known.